Section Hordeum
Section Anisolepis
Section Critesion
Section Stenostachys
Hordeum vulgare L.
Hordeum bulbosum L.
Hordeum murinum L.
Hordeum brevisubulatum subsp. iranicum
Hordeum vulgare subsp. spontaneum
Morphology: Plants in loose tufts, up to 1 m tall, in some especially large types up to 1.5 m. Culms usually erect, sometimes somewhat geniculate at the base. Leaves flat, scabrid or glabrous; auricles long, prominent, linear-falcate, surrounding the culm. Spikes 50-300 mm long, the colour varying from green to purplish or blackish, 10-30 nodes, each bearing three 1-flowered spikelets of which 1, 2 or all 3 are fertile, i.e. two-, four- and six-rowed; the awns normally long and straight, but mutations are found, e.g. 'hooded' and triple-awned forms; rachis brittle or tough. Central spikelet sessile, glumes flattened, usually 10-30 mm long; lemma glabrous or scabrid, mostly near the apex, usually tightly embedding the kernel (though not in naked forms), awn of lemma 30-180 mm long, usually scabrid; anthers 6-10 mm long, yellowish; rachilla short or up to half the length of the palea, with long or short hairs. Lateral spikelets usually sessile, when fertile sessile to pedicellate (3 mm long), when sterile, obtuse to acute or with an awn, almost equally as well-developed as the central one when fertile; glumes 10-20 mm long, more or less flattened.
Life form and reproduction: Summer or winter annual, mainly inbreeding.
Distribution: The natural occurrence of subsp. spontaneum, as far as it can be traced at present, is probably from Greece, Egypt, and Southwest Asia eastwards through Iran, Afghanistan, western Pakistan, and southern Tadzjikistan. Subspecies vulgare has since early times been cultivated throughout the Mediterranean region and Ethiopia and from southwestern Asia eastwards to China and Japan. It is now cultivated in all temperate areas of the world.
Habitat: Grassland areas, meadows as well as semi-arid regions, sometimes on rather salty soil. Subspecies spontaneum and some brittle-rachis forms of subsp. vulgare (H. agriocrithon) are more or less weedy and are often associated with other crops. They grow from sea level in the Mediterranean area and the Middle East to 4500 m in the Himalayas. Depending on the local climate, different forms prevail, e.g. the Oriental barleys of China and Japan are forms characterized by a high frequency of hooded, naked, and brittle types. The Ethiopian forms include deficiens and irregulare; southwestern Asia has mainly two-rowed forms in comparatively dry areas, six-rowed forms in areas with more rainfall.
Status and frequency: Rather common within the distribution area. Landraces are rapidly disappearing from areas where modern cultivars have been introduced.
Chromosome number: Diploid, 2n = 14; artificial tetraploids, 2n = 28, have been produced.
Variation: H. vulgare subsp. vulgare comprising cultivated barley, is the most variable species taxon within the genus. H. vulgare subsp. spontaneum, interpreted as the wild form, shows less morphological variation than subsp. vulgare, even though some subspecific taxa have been distinguished, viz. var. ischnatherum (Cosson) Thell., var. proskowetzii Nábelek, and var. lagunculiforme Bakht. However, investigations of subsp. spontaneum have revealed a large genetic variation and the above-mentioned varieties may not be meaningful. As in other species of Hordeum, some of the variation encountered is phenotypic, due to local climatic/stress factors. Within subsp. vulgare great variation is found and an infraspecific delimitation is outlined below. Of the characters, in which variation is found, the easiest to observe are connected with the spike, e.g. tough/brittle rachis, two-/four-/six-rowed, normal/deficient lateral spikelets, normal/multiflowered spikelet, normal/long-awned glume, long-/short-haired rachilla, short/long hairs on rachis edges, normal/hooded lemma, normal/tripple-awned lemma, covered/naked kernel, and scabrid/hairy lemma.
Morphologically similar species: Small, slender forms of H. vulgare may resemble short, stout forms of H. bulbosum.
Notes: All wild and cultivated forms are interfertile. After a number of years of discussion of how barley had evolved and of the relationships between the different taxa, the accumulated evidence indicates that in fact we are dealing with one single species. De Candolle (1886) was the first to point out the problems regarding the progenitor of barley: was it a two-rowed spontaneum type or an extinct, brittle six-rowed form? During the last 100 years the debate has continued, proponents of the two-rowed progenitor-hypothesis (Körnicke & Werner 1885, Covas 1949, 1950a, b, Helbaek 1953, 1964, Zohary 1959, 1960) challenging the proponents of the six-rowed progenitor- hypothesis (Schiemann 1932, Åberg 1938, 1940, 1948, Nevski 1941, Parodi 1947, Kamm 1954, Takahashi 1955, 1964 in part).
Recent studies of the wild species of Hordeum stress that the general morphological pattern in the Hordeum spike is the three-flowered "triplet" at each node (cf. Bothmer & Jacobsen 1985). This triplet is the functional diaspore with one central, female-fertile flower and two lateral, female sterile flowers, and it serves the dispersal of seed in the most functional way, as three seeds linked together would not be very effective. The progenitor of Hordeum no doubt had a panicle-like inflorescence. The triplet being transformed into a diaspore, the formation of female lateral flowers must be suppressed in order to achieve a functional diaspore dispersal. In most other members of the tribe Triticeae, the diaspore unit is any single flower from a multiflowered spikelet. In Hordeum the capacity to produce female lateral flowers may be assumed still to be present, which is supported by the fact that some of the wild species sometimes produce female fertile lateral flowers and that in H. bogdanii all three flowers of the "triplet" sometimes fall off the more or less tough rachis. For H. vulgare it can be concluded that the selection pressure suppressing the occurrence of female lateral flowers drastically changed when barley was brought into cultivation and the triplet shattered during harvest, storage, and sowing. Thus an original form of H. vulgare would be a two-rowed spontaneum type with a brittle rachis; through mutations and domestication this has produced a number of toughrachis forms, characters which are controlled by rather few genes, i.e. for brittle/tough rachis, two-/six-rowed, naked/not naked, normal/hooded etc. This gives a large number of possible combinations, and gene flow between different forms would produce many further possible combinations. This indicates that a reticulate mode of differentation has taken place, and, therefore, that no simple pattern of phylogeny can be outlined. The system of classification is thus wholly artificial and should be seen as a means of classifying morphologically similar forms, i.e. the wild, two-rowed forms in subsp. spontaneum and all the cultivated ones in subsp. vulgare, even though brittle-rachis types can be produced through mutation and/or hybridization within subsp. vulgare. The six-rowed brittle form of subsp. vulgare found in, e.g. Israel and Tibet and designated as the wild six-rowed form, viz. H. agriocrithon, should be regarded as secondary mutation and hybridization products. Some of the forms certainly behave like weeds, in the sense that they are found in less intensively cultivated fields or areas adjacent to cultivated fields, but they appear to depend wholly on human activity for their continued existence and should be regarded as more or less weedy, hybrid segregations. Below is a key to some intraspecific taxa of higher rank within H. vulgare. It is not intended to be a complete guide to H. vulgare, only to give the principal guidelines. For a higher resolution it is necessary to consult other, more detailed studies (e.g. Mansfeld 1950, Grillot 1959). There is still some disagreement as to which rank should be given to the various taxa. However, during the last 10-20 years the differences of opinion regarding rank appear to have become smaller. The scheme below maintains the cultivated barleys in two main groups, subordinating all forms in these, irrespective of many varieties and cultivars having arisen through hybridization and/or mutation. The somewhat elaborate hierarchical system does not imply that all taxonomical categories must be applied every time a cultivar is mentioned. The Code of Nomenclature for Cultivated Plants (Brickell et al. 1980) provides the use of the generic name followed by the specific epithet and/or the cultivar name, e.g. Hordeum vulgare L. 'Golden Promise', Hordeum 'Golden Promise' or even barley 'Golden Promise'.
Key to the subspecies and some of the major varieties of H. vulgare
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1. Rachis brittle |
2 |
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2. Spike distichous |
subsp. spontaneum (C. Koch.) Thell. |
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2. Spike hexastichous.. subsp. vulgare convar.
vulgare f. agriochriton (Åberg) Bowd. |
3 |
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1. Rachis tough (subsp. vulgare) |
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3. Spike tetra- or hexastichous, central spikelet sessile,
fertile, the lateral ones also sessile and mostly fertile, with rather long awns
(convar. vulgare) |
4 |
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4. Spike compact, hexastichous |
5 |
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5. Caryopses naked |
var. revelatum Körn. |
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5. Caryopses not naked |
var. hexastichon (L.) Aschers. |
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4. Spike lax, subhexa- to tetrastichous |
6 |
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6. Caryopses not naked |
var. vulgare |
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6. Caryopses naked (var. coeleste L.) |
7 |
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7. Awns long |
f. coeleste |
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7. Awns trifurcate |
f. trifurcatum (Schlecht) ined. |
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3. Spike distichous, central spikelet sessile, fertile, the
lateral ones pedicellate, sterile or male fertile, with rather short awns
(convar. distichon (L.) Alef.) |
8 |
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8. Lateral spikelets reduced to glumelike appendages |
var. deficiens (Steud.) ined. |
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8. Lateral spikelets male or neuter, but developed |
9 |
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9. Spikes long, narrow, awns not divergent |
10 |
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10. Caryopses naked |
var. nudum (L.) Alef. |
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10. Caryopses not naked |
var. distichon |
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9. Spikes shortened, broad, awns divergent |
var. zeocrithon (L.) Körn. |
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References: De Candolle (1886), Åberg (1940), Nevski (1941), Åberg & Wiebe (1946), Mansfeld (1950), Covas (1954), Grillot (1959), Harlan (1968), Reid & Wiebe (1968), Trofimovskaya (1972), Hsü (1975), Tzvelev (1976), Murphy et al. (1982), Baum & Bailey (1983a, b), Löve (1984), Giles & Bothmer (1985), Schultze-Motel (1986), Baum (1986, 1987).
Hordeum vulgare subsp. Spontaneum
Morphology: Plants vigorous, up to 135 cm tall. Culms erect to somewhat geniculate; nodes glabrous, pale or occasionally dark brown; basal internode(s) usually bulbous, 1-4 bulbs per culm, ellipsoid, ovoid, or pyriform, lowermost bulb usually best developed 5-45 x 3-17 mm. Leaves flat, up to 9 mm wide, leaf surface with prickle hairs and often also with longer soft hairs especially on the adaxial side; auricles up to 5.5 mm long, often completely surrounding the culm. Spikes 45-165 mm long, light green or greenish-violet. Central spikelet subsessile, glumes 10-25 mm long, flattened at base and with more or less ciliate margins; lemma glabrous, awn of lemma 12-50 mm; anthers 4.5-10 mm, yellow to violet. Lateral spikelets usually well-developed and male; upper glume setaceous, lower glume flattened at the base; lemma occasionally with an awn up to 14 mm; anthers up to 9 mm.
Life form and reproduction: Perennial and obligately outbreeding with a self-incompatibility system.
Distribution: H. bulbosum is found in the Mediterranean region and eastwards to Afghanistan and southern Tadzjikistan. The diploid cytotype is found from Greece and Egypt westwards. The tetraploid cytotype is found from Greece and eastwards, and is also found locally in southern Spain.
Habitat: The ecological amplitude seems to be great, e.g. wet meadows, dry hillsides, roadsides, and abandoned fields are common habitats.
Status and frequency: Unthreatened, locally common.
Chromosome number: Diploid and tetraploid, 2n = 14, 28.
Variation: Although clearly distinguishable, H. bulbosum is a somewhat variable species regarding its size, the size and shape of the spikelets and their hairiness. Several attempts have been made to separate the two cytotypes according to morphological characters. It has been claimed (Katznelson & Zohary 1967, Baum & Bailey 1985a) that the diploid and the tetraploid cytotypes can be separated on such characters as size and shape of bulbs, size, shape, and hairiness of floral parts. However, H. bulbosum shows a considerable variation which does not allow discrimination of the two cytotypes (Jørgensen 1982).
Morphologically similar species: Culms of H. bulbosum without the bulbous swelling may resemble slender forms of H. murinum.
Notes: The tetraploid cytotype is an autoploid with four sets of the I genome that is related to the genome of H. vulgare (Bothmer et al. 1986a). H. bulbosum has got a particular interest for plant breeders because of its resistance to powdery mildew (Jones & Pickering 1978, Xu & Snape 1989). This has led to a number of cytological studies of hybrids between H. bulbosum and H. vulgare (e.g. Kasha & Sadasivaiah 1971, Bothmer et al. 1983, Thomas & Pickering 1988, Xu & Snape 1988). Since the discovery of the ability of diploid H. bulbosum to produce haploids in crosses with H. vulgare (e.g. Lange 1971), there has been a number of investigations of the various factors influencing the haploidization process, i.e. various growth conditions and gentype of the parental material (Fedak 1985, Pickering & Rennie 1990). Tetraploid H. bulbosum has been used to produce haploids in intergeneric crosses with Triticum (e.g. Fedak 1985, Sitch & Snape 1987).
Hordeum bulbosum
Synonyms: H. nodosum L., H. bulbosum L. subsp. nodosum (L.) Baum, H. ciliatum Lam., H. strictum Desf., H. sieberianum Schult. & Schult., H. kaufmanni Regel, Critesion bulbosum (L.) A. Löve.
References: Lein (1948), Katznelson & Zohary (1967), Jørgensen (1982), Baum & Bailey (1985 a, b), Otiz et al. (1985).
Hordeum bulbosum
Morphology: Plants solitary or in more or less dense tufts, up to 80 cm tall. Culms more or less erect, sometimes prostrate due to grazing. Leaves flat, occasionally with involute margins; auricles present, up to 8 mm long, often completely surrounding the culm. Spikes 30-80 mm long, broad, up to 25 mm, green to glaucous to purplish. Central spikelet sessile or on a pedicel up to 2 mm long; glumes compressed, with distinctly ciliate margins; lemma more or less smooth, awn of lemma 20-40 mm long, more or less scabrous; anthers 0.2-2.8 mm long, grey to yellow, sometimes with purple spots. Lateral spikelets well-developed and male fertile; glumes flattened, ciliate; lemma 8-15 mm long, inflated; awn 20-50 mm long; rachilla 2.5-6.5 mm long, slender or gibbous, and yellow.
Life form and reproduction: Winter annual, mostly inbreeding; subsp. glaucum and some forms of subsp. leporinum may, when growing as weeds north of their natural distribution area, behave as summer annuals.
Distribution: Central Europe, Mediterranean region, North Africa, southwestern Asia, Caucasus, southern Uzbekistan, Tadzjikistan, Iran, and Afghanistan; introduced as a weed to most parts of the world, especially subsp. glaucum and subsp. leporinum.
Habitat: The original habitats were probably seasides, sandy riverbeds, and drinking places for animals throughout the Mediterranean region. Presently it is common as a weed in all places with human disturbance.
Status and frequency: Common.
Chromosome number: Diploid, tetraploid, and hexaploid, 2n = 14, 28, 42.
Variation: Very variable in size, depending on the growing conditions. There is also a genetically based variation, reflected in the recognition of three subspecies, one of which occurs both as a tetraploid and a hexaploid cytotype; there is also variation in size, in the hairiness of the leaves, the size of the spikelets, and the shape of the glumes. A large number of intraspecific taxa have been described, mostly based on odd growth forms and insufficient study of previous literature.
Morphologically similar species: Small forms of H. bulbosum.
Notes: H. murinum, 2x, contains a unique genome, called "Y". The polyploid cytotypes may either be autoploids or segmental alloploids.
References: Booth & Richards (1976, 1978), Richards & Booth (1977), Baum & Bailey (1984 a, b, 1985b), Giles (1984), Giles & Lefkovitch (1986).
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1. Central spikelet sessile to subsessile; lateral spikelet
including awn usually shorter than that of the central spikelet; palea of the
lateral spikelet almost glabrous |
subsp. murinum |
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1. Central spikelet pedicellate, pedicel somewhat shorter than
that of the lateral spikelet; lateral spikelet including awn usually longer than
that of the central spikelet; palea of the lateral spikelet pubescent |
2 |
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2. Lateral spikelet excluding awn much longer than the central
one; palea of the lateral spikelet scabrid in the lower half. Anthers of lateral
and central spikelets yellowish, of about the same size, 0.9-3.2 mm
long |
subsp. leporinum |
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2. Lateral spikelet excluding awn of about the same size as
the central one; palea of the lateral spikelet distinctly pilose, especially so
in the lower half. Anthers of the central spikelet with small purple spots,
0.2-0.6 mm long, much shorter than those of the lateral ones, which are 1.2-1.8
mm long |
subsp. glaucum |
Morphology: Plants usually large, 30-60 cm tall. Spike usually green; the relatively small lateral spikelets lending the spike a thin appearance. Central spikelet sessile to subsessile, about the size of the lateral ones excluding awns; anthers of the central spikelet of about the same length as those of the lateral ones, 0.8-1.4 mm. Palea of the lateral spikelets almost glabrous; rachilla of the lateral spikelets pale, thin.
Distribution: Northern and western Europe, from the Atlantic to the Caucasus area, usually not reaching the Mediterranean region.
Chromosome number: Tetraploid, 2n = 28.
Synonyms: H. murinum L. var. arenaria Hook, f., H. murinum L. var. intermedium Beck, Critesion murinum (L.) A. Löve subsp. murinum.
subsp. leporinum (Link) Arcangeli
Morphology: Plants usually large, 30-110 cm tall, rather stout, winter annual. Spike green at anthesis, but often more or less purple in the seed stage; the large lateral spikelets lending the spike a thick appearance. Central spikelet pedicellate, usually much smaller than the lateral ones excluding the awn; anthers of central spikelet shorter (0.9-3 mm) or as long as the ones of the lateral spikelets (1.2-3.2 mm). Palea of the lateral spikelets scabrous in the lower half.
Hordeum murinum subsp. leporinum 4x
Distribution: Mediterranean region, eastwards to Afghanistan; tetraploids probably throughout the area, hexaploids from Turkey eastwards to Iran.
Chromosome number: Tetraploid and hexaploid, 2n = 28 and 42.
Synonyms: H. leporinum Link, H. murinum L. var. leporinum (Link) Bory & Chaub., H. murinum L. var. chilense Brongn., H. pseudomurinum W.D.J. Koch, H. murinum L. var. glaucescens Doell, H. ambiguum Doell, H. murinum L. var. velutina Speg., H. leporinum Link var. simulans Bowden, Critesion murinum (L.) A. Löve subsp. leporinum (Link) A. Löve, C. simulans (Bowden) A. Löve.
subsp. glaucum (Steudel) Tzvelev
Morphology: Plants rather small, 15-40 cm tall, slender, spring annual. Spike green to glaucous, when ripe often brownish; the relatively small lateral spikelets lending the spike a more gracile appearance than in the other subspecies. Central spikelet pedicellate, pedicels not much shorter than the lateral ones; anthers of the central spikelets (0.2-0.6 mm long) more or less covered with purple spots, much shorter than those of the lateral spikelets (1.2-1.8 mm). Palea of the lateral spikelets more or less densely pilose, especially in the lower half.
Distribution: Southern Mediterranean region and eastwards to Iran, Afghanistan, and Kashmir.
Chromosome number: Diploid, 2n = 14.
Notes: Some forms from North Africa lack cilia on the margins of the central glumes; forms from the Kashmir region have rather short pedicels on the central spikelets.
Synonyms: H. glaucum Steud., H. leporinum Link subsp. glaucum (Steud.) Booth & Richards, H. murinum L. var. leptostachys Batt. & Trab., H. stebbinsii Covas, Critesion glaucum (Steud.) A. Löve.
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Hordeum pusillum Nuttal
Hordeum intercedens Nevski
Hordeum euclaston Steudel
Hordeum flexuosum Steudel
Hordeum muticum Presl
Hordeum chilense Roemer & Schultes
Hordeum cordobense Bothmer, Jacobsen & Nicora
Hordeum stenostachys Godron
Morphology: Plants 10-50 cm high, in loose tufts. Culms erect to somewhat geniculate; nodes glabrous; in small specimens the spikes sometimes mature halfway up in the uppermost leaf sheath. Leaves mostly flat, glabrous to densely hairy; auricles lacking. Spikes 30-75 mm long, pale to yellowish green. Central spikelet sessile, glumes 9-15 mm long, flattened at the base, up to 1 mm broad; lemma glabrous to densely pubescent, awn of lemma 5-9 mm long; anthers 0.7-1.5 mm long, yellow. Lateral spikelets usually sterile, aristulate to aristate; upper glume 7-14 mm long, setaceous, lower glume broadly flattened at the base.
Life form and reproduction: Annual and inbreeding.
Distribution: Most of the USA except the westernmost part, and a few records from Canada and Mexico.
Habitat: Grasslands, borders of marshes, disturbed places such as roadsides and ruderal habitats, often on alkaline soil, at altitudes up to 1500 m.
Status and frequency: Common except in the northeastern USA.
Chromosome number: Diploid, 2n = 14.
Variation: H. pusillum is variable in some characters, e.g. pubescent forms occur in southwestern USA, while flattened upper glumes are found all over the distribution area, although most frequently in the central parts.
Morphologically similar species: H. intercedens and H. euclaston (South America).
Synonyms: H. riehlii Steud., H. pusillum Nutt. var. pubens Hitchcock, Critesion pusillum (Nutt.) A. Löve subsp. pusillum.
References: Covas (1949, 1970), Bothmer et al. (1982), Baum & Bailey (1986).
Morphology: Plants up to 40 cm tall, with many culms, but under poor conditions 5-10 cm with a single culm. Culms slender, erect or somewhat geniculate; sometimes with spikes that mature halfway up in the uppermost leaf sheath; nodes usually pubescent. Leaves flat or rarely with somewhat involute margins, sparsely to densely pubescent; auricles lacking; the leaf sheaths have stripes of hairs down to the nodes. Spikes 25-60 mm long, pale green. Central spikelet sessile, glumes 9-17 mm long, flattened at the base, up to 0.8 mm broad; lemma sparsely pubescent in the lower part, but glabrous in the upper part, awn of lemma 5-10 mm long; anthers 0.6-1.2 mm long, yellow. Lateral spikelets usually sterile or rudimentary, obtuse to acute; upper glume usually setaceous, lower glume flattened at the base.
Life form and reproduction: Annual and inbreeding.
Distribution: Endemic to southwestern California, adjacent Santa Barbara Islands, and northwestern Baja California of Mexico.
Habitat: Along rivers, sometimes saline and often flooded areas such as alkaline vernal pools in shrublands, and hillsides, at low altitude.
Status and frequency: The species is still rather common in Baja California and at most sites in the Santa Barbara Islands in undisturbed habitats, but on mainland California it has declined and is now found in only very few sites.
Chromosome number: Diploid, 2n = 14.
Variation: H. intercedens shows a considerable variation. Some populations, especially from central California, are almost glabrous. Most material has obtuse to acute lateral spikelets, but a few populations have shortly aristulate ones.
Morphologically similar species: H. pusillum (glabrous leaf sheaths) and H. euclaston (South America).
Notes: H. intercedens was formerly included in H. pusillum by several authors (e.g. Covas 1949; Hitchcock 1951; Wiggins 1980). It has, however, proved to be distinct in both morphology and distribution.
Synonym: It has formerly been listed as H. pusillum in various floras of the USA. References: Bothmer et al. (1982), Baum & Bailey (1986, 1988).
Morphology: Plants (5-)20-40 cm tall, in loose tufts. Culms mostly erect; nodes glabrous; in small specimens, the spikes sometimes mature halfway up in the uppermost leaf sheath. Leaves mostly flat, more or less pubescent; auricles lacking. Spikes 20-70 mm long, pale to yellowish green. Central spikelet sessile, glumes 7- 16 mm long, flattened, lanceolate in the basal part, up to 1 mm broad; lemma glabrous or more or less pubescent, awn of lemma 5-11 mm long; anthers 0.3-1.3 mm long, yellow. Lateral spikelets usually sterile, acute to acuminate; upper glume setaceous, lower glume broadly flattened at the base.
Life form and reproduction: Annual and inbreeding.
Distribution: Central Argentina, Uruguay, and southern Brazil.
Habitat: In pastures and sandy steppes, near ditches and lakes, and as a weed near ruderal areas, at low altitude, thrives in moderately disturbed habitat.
Status and frequency: Rather common within the distribution area.
Chromosome number: Diploid, 2n = 14.
Variation: H. euclaston shows a wide range of variation in most of its characters, especially outside the main distribution area in central Argentina, e.g. hairy forms in Mendoza or small forms in Patagonia.
Morphologically similar species: H. flexuosum (perennial), H. pusillum (North America), and H. intercedens (North America).
Synonyms: H. subfastigiatum Doell, H. pusillum Nutt. subsp. euclaston (Steud.) Covas and var. euclaston (Steud.) Haum.; hairy forms have been described as var. pubescens Nevski and var. puberulum Parodi & Nicora, Critesion pusillum (Nutt.) A. Löve subsp. euclaston (Steud.) A. Löve.
References: Covas (1970), Bothmer et al. (1982), Baum & Bailey (1986).
Morphology: Plants up to 50 cm tall, in loose to dense tufts. Culms mostly erect; nodes glabrous. Leaves usually flat, scabrid or rarely pubescent; auricles lacking. Spikes 35-70 mm long, appearing contracted with adpressed glumes, pale to yellowish green, sometimes with a purplish tinge. Central spikelet sessile, glumes 5-9 mm long, flattened, narrowly ovate in the lower part, 0.3-0.6 mm broad; lemma mostly glabrous, scabrid at apex, awn of lemma 2-5 mm long; anthers 1-2.5 mm long, yellow, sometimes purplish, rachilla somewhat thick, flattened, usually glabrous. Lateral spikelets usually sterile, obtuse to acute; upper glume setaceous, lower glume broadly flattened, mostly abruptly narrowed with a distinct shoulder or sometimes teeth.
Life form and reproduction: Perennial, mainly inbreeding.
Distribution: The centre of distribution is in the province of Buenos Aires, Argentina, with scattered localities in adjacent areas, including Uruguay. Older collections supposedly collected in Colombia are puzzling, being from outside the main distribution area. No recent collections are known.
Habitat: Pastures in the pampas, riverbeds, along ditches, and in somewhat saline places near lakes, at low altitude; thrives with some disturbance in the habitat.
Status and frequency: Rather common within the distribution area. Chromosome number: Diploid, 2n = 14.
Variation: The variation in H. flexuosum relates mostly to the size of the plants, as those from dry and saline places are smaller and more slender and sometimes also flower before the spike has emerged from the upper leaf sheath; those from saline habitats also have shorter spikes, and the glumes often lack shoulders. In northernmost Argentina and Uruguay the plants have longer glumes that are not as adpressed to the spike.
Morphologically similar species: H. euclaston (annual) and smaller specimens of H. stenostachys.
Synonyms: H. bonariense Parodi & Nicora, H. pusillum Nutt. subsp. flexuosum (Steud.) Covas, Critesion flexuosum (Steud.) A. Löve.
References: Covas (1970), Bothmer et al. (1982), Baum & Bailey (1986).
Morphology: Plants up to 50 cm tall, in dense tufts. Culms often very slender, mostly erect; nodes glabrous. Leaves flat, the uppermost ones usually with involute margins, surface more or less densely scabrid to hairy; auricles lacking. Spikes 30-70 mm long, greenish to greyish purple to bluish. Central spikelet sessile, glumes 4-8 mm long, setaceous to somewhat flattened in the basal part; lemma glabrous, sparsely scabrid hairy in the upper part, apex of the lemma muticous to aristulate, 0.5-4 mm long; anthers 1.3-2.7 mm long, yellow to purple; rachilla often lacking, if present up to 4.5 mm long. Lateral spikelets usually rudimentary, muticous to acuminate; upper glume more or less setaceous, lower glume flattened to setaceous.
Life form and reproduction: Perennial, open pollinated to inbreeding.
Distribution: Northwestern Argentina, northeastern Chile, Bolivia, Peru, Ecuador, and Colombia. The distribution in the latter two countries is puzzling as specimens have not been recollected recently.
Habitat: Wet Andean pastures or somewhat drier puna steppes, above 3000 m.
Status and frequency: Common in Andean areas, except in Colombia and Ecuador.
Chromosome number: Diploid, 2n = 14.
Variation: H. muticum shows a rather large variation in many characters, e.g. hairiness of leaves and lemmas, muticous to aristate lemmas, and narrow to broad spikes; in northern Argentina and Bolivia forms with long glumes and aristate lemmas occur, in these characters resembling slender forms of H. halophilum.
Morphologically similar species: Short-awned and short-glumed forms of H. halophilum.
Notes: The long-awned and long-glumed forms occurring in northern Argentina and Bolivia appear to approach H. halophilum in morphology, but the limited information available suggests that they belong to H. muticum.
Synonyms: H. andicola Griseb., H. secalinum Schreb. var. parviflorum Hack., Critesion muticum (Presl) A. Löve.
References: Hunziker & Maumús (1964), Bothmer et al. (1980).
Morphology: Plants in loose to dense tufts, up to 70 cm tall. Culms slender to stout, ascending to erect; nodes glabrous. Leaves flat, glabrous to more or less densely hairy; auricles lacking. Spikes 40-80 mm long, pale to purplish green. Central spikelet sessile, glumes 8-23 mm long, often spreading at maturity, distinctly flattened at the base; lemma glabrous, sparsely scabrid towards the apex, awn of lemma 4-12 mm long; anthers 1.3-2.8 mm long, yellow, rarely violet; rachilla usually thick, more or less flattened, rarely rudimentary. Lateral spikelets muticous; upper glume more or less setaceous to somewhat flattened, lower glume distinctly flattened at the base.
Life form and reproduction: Perennial, inbreeding or open pollinated.
Distribution: Central Chile and the westernmost parts of the provinces of Neuquen and Rio Negro, Argentina.
Habitat: Roadsides, pastures; in mesic as well as xeric habitats, but in Argentina mostly in mesic; at altitudes up to 1000 m.
Status and frequency: The species is rather common within the distribution area.
Chromosome number: Diploid, 2n = 14.
Variation: H. chilense has a very wide range of variation in its morphological characters, e.g. in the size of the floral parts, where the Argentinian and some of the Chilean material has much longer glumes and lemmas than the coastal Chilean populations.
Morphologically similar species: H. brachyantherum (North America), H. roshevitzii (Central Asia), and H. capense (southern Africa) may resemble H. chilense.
Notes: H. chilense var. magellanicum is now considered a subspecies of H. patagonicum.
Synonyms: H. secalinum Schreb. var. chilense (Brongn.) Desv., H. chilense Brongn. var. pseudosecalinum Haum., H. depauperatum Steud., H. cylindricum Steud., H. apertum Phil., H. chilense Roem. & Schult. var. pilosum Nevski, Critesion chilense (Roem. & Schult.) A. Löve.
References: Bothmer et al. (1980).
Morphology: Plants in small, loose tufts, up to 60 cm tall, mostly with few culms. Culms slender, erect; nodes glabrous. Leaves flat, sparsely to densely scabrid; auricles lacking. Spikes slender, 55-85 mm long and 3-4 mm broad, pale green. Central spikelet sessile, glumes 4-7 mm long, distinctly flattened, up to 0.5 mm broad; lemma sparsely scabrid, especially on the 7(-9) distinct nerves, apex of lemma acuminate, not awned, 1.5-4.5 mm long; anthers 1.8-3 mm long, yellow; rachilla usually lacking, when present up to 2.5 mm long. Lateral spikelets usually rudimentary; upper glume 4-7 mm long, more or less setaceous to somewhat flattened, lower glume flattened.
Life form and reproduction: Perennial, more or less inbreeding.
Distribution: Central and northern Argentina.
Habitat: Grasslands, often grazed, at altitudes up to 1000 m.
Status and frequency: Scattered within the distribution area.
Chromosome number: Diploid, 2n = 14.
Variation: H. cordobense shows little variation.
Morphologically similar species: May resemble slender forms of H. stenostachys.
Notes: The name H. compressum Griseb. has previously been used for this species, but the type specimen belongs to H. stenostachys.
Synonyms: H. compressum auct., non Griseb., H. compressum Griseb. var. tenuispicatum Hack. & Stuck., Critesion cordobense (Bothmer et al.) A. Löve.
References: Covas (1970), Bothmer et al. (1980).
Morphology: Plants in dense tufts, up to 120 cm tall. Culms stout, erect; nodes glabrous. Leaves flat, glabrous to densely hairy; auricles lacking. Spikes 65-110 mm long and 4-5 mm broad, pale green. Central spikelet sessile, glumes 4-11 mm long, up to 0.5 mm broad, distinctly flattened at the base; lemma sparsely to more or less densely pubescent, apex of lemma aristulate to aristate 2.5-7 mm long; anthers 2.2-4.4 mm long, yellow; rachilla often lacking. Lateral spikelets rudimentary; upper glume setaceous to somewhat flattened, lower glume distinctly flattened.
Life form and reproduction: Perennial, mainly inbreeding but some outbreeding may occur.
Distribution: Central and northern Argentina, Uruguay, and southernmost Brazil.
Habitat: Pastures, wastelands, and roadsides at altitudes up to 1000 m.
Status and frequency: Common within the distribution area.
Chromosome number: Diploid, 2n = 14.
Variation: H. stenostachys is rather variable in size, hairiness, and size of spike-lets, material from the northeastern area tending to be larger in several characters.
Morphologically similar species: Small specimens of H. stenostachys may resemble larger specimens of H. flexuosum and stouter specimens of H. cordobense.
Synonyms: H. compressum Griseb., H. secalinum Schreb. var. puberulum O. Kuntze, H. secalinum Schreb. var. scabriusculum O. Kuntze, H. compressum Griseb. var. superatum Hack., H. chilense Brongn. var. muticum (Presl) Haum. f. longearistatum Haum., H. chilense Brongn. var. compressum (Griseb.) Haum. f. elongatum Haum., Critesion stenostachys (Godr.) A. Löve.
References: Covas (1970), Bothmer et al (1980).
Hordeum pubiflorum Hooker f.
Hordeum halophilum Grisebach
Hordeum comosum Presl
Hordeum jubatum L.
Hordeum arizonicum Covas
Hordeum procerum Nevski
Hordeum lechleri (Steudel) Schenck
Morphology: Plants small to medium sized, 10-40 cm tall, forming loose tufts. Culms geniculate to erect, slender; nodes glabrous. Leaves flat to involute, densely pubescent on the adaxial side, hairs long; auricles lacking. Spikes 30-60 mm long, laterally compressed, blackish to reddish. Central spikelet sessile, glumes 18-25 mm long, setaceous, pubescent to the middle, scabrid above, spreading at maturity; lemma glabrous or rarely sparsely hairy at the apex, awn of lemma 10-16 mm long; anthers 1-1.5 mm long. Lateral spikelets male flowering or sterile; glumes setaceous, sparsely pubescent; lemma 4-7 mm long, pubescent; awn of lemma 4-6 mm long, pubescent.
Life form and reproduction: Perennial, predominantly inbreeding.
Distribution: Primarily in Tierra del Fuego and the Magellanes, but also in the province of Santa Cruz in Argentina; a single record from the region of Nuble in Chile.
Habitat: Grows in lowland to high mountain meadows, in both saline and freshwater habitats at altitudes up to 2000 m.
Status and frequency: H. pubiflorum is very common and often the dominating element in the vegetation.
Chromosome number: Diploid, 2n = 14.
Variation: The taxonomy of H. pubiflorum and especially the distinction from H. halophilum (see under this species) is at present not clear. Populations of H. pubiflorum from the northern part of the distribution area are rather tall with blackish spikes, while populations from the southern part are smaller, sometimes with reddish spikes. In the overlapping zone intermediate forms occur. Populations from the northern part are also less hairy than the southern ones.
Morphologically similar species: H. halophilum and H. lechleri.
Notes: Nevski (1941) included H. pubiflorum in H. comosum as var. pubiflorum (Hook, f.) Thell. Bothmer & Jacobsen (1985) regarded H. pubiflorum including H. halophilum sensu lato as very variable and possibly containing several subspecies. The distribution of H. pubiflorum was thus regarded as very large, covering southern South America from Tierra del Fuego in Argentina to Bolivia, contrary to the more limited distribution presented here.
Synonyms: H. comosum Presl var. pubiflorum (Hook. f.) Thell., Critesion pubiflorum (Hook, f.) A. Löve subsp. pubiflorum.
References: Hunziker & Maumús (1964), Baden & Bothmer (1994).
Morphology: Plants small to medium sized, up to 40 cm tall, forming loose tufts. Culms erect to geniculate, slender; nodes glabrous. Leaves flat, margin sometimes involute, shortly pubescent on the adaxial side; auricles lacking. Spikes 35-50(-80) mm long, laterally compressed, reddish. Central spikelet sessile, glumes 10-20 mm long, setaceous, spreading at maturity; lemma glabrous, rarely pubescent at the apex, awn of lemma 6-10 mm long; anthers 0.8-1.4 mm long, violet. Lateral spikelets sterile; glumes setaceous; lemma including awn 4-5 mm long.
Life form and reproduction: Perennial and mainly inbreeding.
Distribution: From Tierra del Fuego northwards on both sides of the Andes through Argentina and Chile and scattered in Bolivia and Peru.
Habitat: Grows in lowland to high mountain meadows, in both saline and fresh water environments at altitudes up to 4000 m.
Status and frequency: The species is common all over the northwestern part of southern South America. In the southern part of its distribution it often occurs in large numbers where found, but in the northern part it is more scattered.
Chromosome number: Diploid, 2n = 14.
Variation: H. halophilum is very variable. Two subspecific taxa have been recognized. In some populations from the province of Neuquen to La Rioja, small forms (up to 20 cm tall) occur with very short spikes, awns of lemma, and glumes (20-30 mm, 4-6 mm, and 8-10 mm long, respectively). These have been recognized as H. halophilum var. breviaristatum Parodi & Nicora. Other populations with tall and glabrous forms belong to var. halophilum.
Morphologically similar species: Populations belonging to var. breviaristatum resemble H. muticum (for differences, see the latter species), H. chilense, H. pubiflorum, and H. lechleri.
Notes: The relationship between H. pubiflorum and H. halophilum is not clear at present, and they may prove to be one species with several subspecies. Nevski (1941) included H. halophilum in H. comosum.
Synonyms: Critesion pubiflorum (Hook, f.) A. Löve subsp. halophilum (Griseb.) A. Löve.
References: Hunziker & Maumús (1964), Baden & Bothmer (1994).
Morphology: Plants small to medium sized, 10-45 cm tall, rarely up to 75 cm, forming dense tufts with a well-developed root system. Culms geniculate to erect, slender; nodes glabrous. Leaves flat, sometimes with involute margins, shortly pubescent on the adaxial side, rarely glabrous; auricles present on the basal leaves, up to 0.5 mm long. Spikes 40-100 mm long, yellowish to black purple, before and after anthesis, acute and fusiform, at full maturity with spreading glumes. Central spikelet sessile, glumes 20-35 mm long, setaceous; lemma 8-12 mm long, glabrous, awn of lemma 18-22 mm long; anthers 2-2.5 mm long, yellow. Lateral spikelets usually rudimentary, rarely male flowering; glumes 20-30 mm long; awn of lemma 15-30 mm long.
Life form and reproduction: Perennial and mainly inbreeding.
Distribution: Confined to Andean areas in Chile and Argentina north to the province of Mendoza.
Habitat: Grows in dry habitats, i.e. steppes, dry hillsides of the Andes up to 4000 m.
Status and frequency: H. comosum is rather common in its distribution area. Chromosome number: Diploid, 2n = 14.
Variation: Some variation in colour and size occurs. Forms with bifid paleas and glabrous lodicules have been recognized as var. bifidum Parodi & Nicora with the same distribution as var. comosum.
Morphologically similar species: H. comosum resembles other species with long awns and glumes, but is rather distinct and recognizeable with its aristate lateral spikelets.
Synonyms: H. andinum Trin., Critesion comosum (Presl) A. Löve. References: Hunziker & Maumús (1964), Baden & Bothmer (1994).
Hordeum jubatum
Morphology: Plants medium sized, 20-60 cm tall, densely caespitose, with many culms, under dry conditions few. Culms geniculate to erect, slender; nodes glabrous. Leaves often flat, scabrid, pubescent on the adaxial side and glabrous on the abaxial side; auricles lacking. Spikes 30-100 mm long, with a whitish green to light purplish tinge, usually somewhat nodding. Central spikelet sessile, glumes 35-80 mm long, setaceous, spreading at maturity; lemma glabrous, awn of lemma 25-90 mm; anthers 0.6-1 mm long, yellow. Lateral spikelets male or sterile; glumes setaceous, spreading at maturity; lemma 4-5 mm long, awn of lemma 2-7 mm long.
Life form and reproduction: Perennial, in drier habitats sometimes biennial (in some floras cited as annual); largely inbreeding.
Distribution: Native from Mexico northwards through the USA, Canada, and Alaska to eastern Siberia. Introduced to South America, Europe, and Central Asia, where, as a weed, it has expanded its distribution considerably.
Habitat: Grows naturally in meadows, prairies around riverbeds and seasonal lakes, often in saline habitats. The species is often found along roadsides and on other rural areas. Occurs from sea level up to 3000 m.
Status and frequency: Common; in natural habitats it forms large stands and may in pastures become a noxious weed.
Chromosome number: Tetraploid, 2n = 28.
Variation: H. jubatum shows considerable variation, especially in the length of the glumes, and forms with short glumes have been described as H. adscendens H.B.K. and H. caespitosum Scribn. Some of these forms may be stabilized hybrids between H. jubatum and H. brachyantherum (cf. Baum 1980).
Morphologically similar species: Morphologically H. jubatum resembles the diploid H. comosum. Covas (1949) regarded this species as one of the possible ancestors of H. jubatum. Forms of H. jubatum with short glumes bear a certain resemblance to H. brachyantherum, H. arizonicum, H. lechleri, and H. procerum.
Notes: H. jubatum is a segmental alloploid and is closely related to H. brachyantherum.
Synonyms: Hordeum caespitosum Scribn., H. adscendens H.B.K., Critesion geniculatum Raf., C. jubatum (L.) Nevski subsp. jubatum, C. adscendens (H.B.K.) A. Löve.
References: Bowden (1962), Mitchell & Wilton (1964), Mitchell (1967), Baum (1980), Baum & Bailey (1988), Baden & Bothmer (1994).
Morphology: Plants medium sized, 30-70 cm tall, with few culms, forming slender tufts. Culms mostly erect, rarely geniculate, often with spikes that mature in the uppermost leaf sheaths; nodes glabrous. Leaves flat, glaucous, scabrid to densely pubescent on the adaxial side; older basal sheaths pubescent, upper sheaths glabrous; auricles lacking. Spikes 40-120 mm long, pale green. Central spikelet sessile, glumes 17-28 mm long spreading at maturity, flattened at the base, setaceous above the middle; lemma glabrous, awn of lemma 13-22 mm long; anthers 1-1.9 mm long, yellow. Lateral spikelets sterile and rudimentary; glumes usually unequal, setaceous above the middle, flattened at the base.
Life form and reproduction: Perennial or biennial, sometimes even annual, and mainly inbreeding.
Distribution: Mainly in southern Arizona, but also a few locations in the southeastern part of California and northern Mexico.
Habitat: In saline habitats along ditches, water canals, and ponds, at altitudes up to 800 m.
Status and frequency: It may be threatened with extinction as its natural habitats are being turned into concrete-covered canals or irrigated fields.
Chromosome number: Hexaploid, 2n = 42. Variation: H. arizonicum shows little variation.
Morphologically similar species: H. jubatum, H. lechleri (South America), and H. procerum (South America).
Notes: H. arizonicum is a segmental alloploid, including genomes from H. jubatum and H. pusillum (Rajhathy & Symko 1966) or possibly H. intercedens (Baum & Bailey 1988).
Synonyms: H. adscendens sensu Hitchcock, non H.B.K., Critesion arizonicum (Covas) A. Löve.
References: Covas (1949), Rajhathy & Symko (1966), Craig & Fedak (1985), Baum & Bailey (1988), Baden & Bothmer (1994).
Morphology: Plants large, 40-80 cm tall, sometimes with many culms, under poor conditions up to 30 cm and one culm. Culms stiff, erect, rarely geniculate; sometimes with mature spikes in the uppermost leaf sheaths; nodes glabrous. Leaves flat, rarely involute, scabrid and pubescent on the adaxial side; older basal sheaths pubescent, upper sheaths glabrous; auricles lacking. Spikes 50-110 mm long, pale green. Central spikelet sessile, glumes 12-21 mm long spreading at maturity, more or less setaceous; lemma glabrous to sparsely scabrid, awn of lemma 9-17 mm long; anthers 1.2-1.8 mm long, yellow. Lateral spikelets sterile and more or less rudimentary, rarely male; glumes more or less equal, setaceous.
Life form and reproduction: Perennial, often short-lived, and inbreeding.
Distribution: Primarily in the provinces of Buenos Aires, Neuquen, Rio Negro, and La Pampa of Central Argentina, but rare in Chubut; a single record from Uruguay.
Habitat: In grassy places, salt marshes, saline riverbeds, and meadows at altitudes up to 1200 m.
Status and frequency: The species is not common in central Argentina; but it sometimes occurs in large stands.
Chromosome number: Hexaploid, 2n = 42.
Variation: H. procerum shows very little variation.
Morphologically similar species: H. lechleri, H. jubatum, and H. arizonicum.
Notes: H. procerum is a segmental alloploid related to H. lechleri and H. arizonicum.
Synonyms: H. hexaploidum Covas, Critesion procerum (Nevski) A. Löve.
References: Covas (1951), Baden & Bothmer (1994).
Morphology: Plants medium sized, 25-65 cm tall, forming loose to dense tufts. Culms geniculate to erect, coarse; nodes glabrous. Leaves flat, sometimes with involute margins, scabrid and hairy with long hairs; auricles lacking. Spikes 50-120 mm long, bright purple or greenish, erect to nodding. Central spikelet sessile, glumes 27-55 mm long, setaceous, spreading at maturity; lemma scabrid at the apex and on the margins, awn of lemma 35-45 mm long; anthers 1-1.5 mm long, yellow. Lateral spikelets rudimentary, male flowering or rarely perfect; glumes 30-60 mm long, setaceous; lemma 6-7 mm long, scabrid at the apex, awn of lemma 7-10(-15) mm long.
Life form and reproduction: Perennial and mainly inbreeding.
Distribution: Confined to Chile and Argentina from the province of Mendoza and southwards to Tierra del Fuego. It also occurs on the Falkland Islands.
Habitat: Grows in river valleys, meadows, roadsides, and disturbed areas; occurs in both saline and fresh water habitats at altitudes up to 2000 m.
Status and frequency: H. lechleri is very common and is often a dominant species in the vegetation.
Chromosome number: Hexaploid, 2n = 42.
Variation: H. lechleri shows only limited variation in the northern part of its distribution area. However, in the southern part and especially in Tierra del Fuego some variation occurs in colour (green to violet) and size.
Morphologically similar species: H. procerum, H. comosum, H. pubiflorum, H. halophilum, and H. jubatum.
Notes: H. lechleri is of alloploid origin, like H. procerum and H. arizonicum.
Synonyms: Elymus lechleri Steud., Critesion lechleri (Steud.) A. Löve.
References: Baden & Bothmer (1994).
Hordeum marinum Hudson
Hordeum secalinum Schreber
Hordeum capense Thunberg
Hordeum bogdanii Wilensky
Hordeum roshevitzii Bowden
Hordeum brevisubulatum (Trinius) Link
Hordeum brachyantherum Nevski
Hordeum depressum (Scribner & Smith) Rydberg
Hordeum guatemalense Bothmer, Jacobsen & Jørgensen
Hordeum erectifolium Bothmer, Jacobsen & Jørgensen
Hordeum tetraploidum Covas
Hordeum fuegianum Bothmer, Jacobsen & Jørgensen
Hordeum parodii Covas
Hordeum patagonicum (Haumann) Covas
Morphology: Plants with single culms or more or less densely tufted, up to 50 cm tall. Culms somewhat slender, erect to geniculate; spikes sometimes mature halfway up in the uppermost leaf sheath; nodes glabrous. Leaves mostly flat, glabrous or more or less densely covered with soft hairs; auricles usually lacking, if present very small. Spikes 15-70 mm long, dense, stiff, ovate, green to glaucous, sometimes with a purple tinge on the glumes, rachis brittle rather late in maturity. Central spikelet sessile, glumes 14-26 mm long, setaceous or compressed; lemma smooth or somewhat scabrid, awn of lemma 6-18 mm long; anthers 0.8-1.3 mm long, yellow. Lateral spikelets with a long awn, sterile; lower glume setaceous to compressed or broadly winged, upper glume more or less setaceous.
Life form and reproduction: Winter or summer annual, inbreeding.
Distribution: Western and central Europe, the Mediterranean region, southwestern Asia, Caucasus, Uzbekistan, Iran, Afghanistan, and western Pakistan; it has been introduced to many other parts of the world, where it occurs as a weed.
Habitat: Mainly confined to saline meadows or marshes along the coast or inland, sometimes in river beds. It is also found as a weed on waste ground and in pastures.
Status and frequency: Rather common in the areas where it occurs.
Chromosome number: Diploid and tetraploid, 2n = 14, 28.
Variation: Very variable in size, depending on the growth conditions. There is also a genetically based variation, reflected in the recognition of two subspecies, one occuring both as a diploid and a tetraploid cytotype; there is also variation in the hairiness of the leaves, the size of the spikelets, and the shape of the glumes; hairy forms have previously received taxonomical recognition.
Morphologically similar species: Slender forms (prior to anthesis) have often been identified as H. secalinum and H. depressum (North America).
Notes: The tetraploid cytotype seems to be of autoploid origin with a genetic mechanism for diploidization (Bothmer et al. 1989c, Linde-Laursen et al. 1992b).
References: Covas (1970), Baum & Bailey (1984 a, b), Bothmer et al. (1989c).
Hordeum marinum
Key to the subspecies of H. marinum
|
1. Glumes of the lateral spikelets heteromorphous, the lower
one with a distinctly flat and wide wing |
subsp. marinum |
|
1. Glumes of the lateral spikelets isomorphous, setaceous, the
lower one sometimes flattened, never with a conspicuously wide wing |
subsp. Gussoneanum |
Morphology: Summer or winter annual; leaves usually flat, 1.5-8 mm broad; lower lateral glume with a more or less broad wing.
Distribution: Native in the Mediterranean region, especially in the western part. Chromosome number: Diploid, 2n = 14.
Synonyms: H. maritimum With., H. secalinum Schreb. subsp. marinum (Huds.) Fouill. & Lit., H. maritimum Pourr., H. rigidum Roth, H. pubescens Guss., H. marinum Huds. var. pubescens (Guss.) Nevski, Critesion marinum (Huds.) A. Löve.
subsp. gussoneanum (Parlatore) Thellung
Morphology: Summer annual; leaves flat or with involute margins, 1.5-4 mm broad; lower lateral glume setaceous or slightly compressed.
Distribution: The diploid cytotype of subsp. gussoneanum is mostly found in the eastern Mediterranean to southwestern Asia. The tetraploid cytotype occurs from Turkey to Afghanistan.
Chromosome number: Diploid and tetraploid, 2n = 14, 28.
Synonyms: H. gussoneanum Parl., H. marinum Huds. var. gussoneanum (Parl.) Täckholm, H. geniculatum All., H. hystrix Roth, H. utriculatum Bertero, H. pratense Huds. var. annuum Lange, H. gussoneanum Parl. var. uniflorum Lojacono, H. pavisii Preaub., Critesion geniculatum (All.) A. Löve, C. hystrix (Roth) A. Löve.
|
Hordeum marinum |
||
Hordeum marinum subsp. gussoneanum 2x
Morphology: Plants up to 85 cm tall, in loose tufts. Culms erect, usually slender; basal leaf sheaths densely hairy; nodes glabrous. Leaves flat, sometimes with involute margins, scabrid and densely hairy with long hairs; auricles present on the basal leaves, up to 1 mm long. Spikes 30-70 mm long, pale green or rarely pale greenish violet. Central spikelet sessile, glumes 8-15 mm long, setaceous, lemma glabrous, awn of lemma 5-15 mm; anthers 3.5-5 mm long, yellow. Lateral spikelets often developed in the middle of the spikes, usually male, rarely with pistil.
Life form and reproduction: Perennial, with a poorly developed root system; mainly outbreeding.
Distribution: From southernmost Sweden and central Denmark along the Atlantic coast of Europe to Spain; scattered locations in the Mediterranean and in inland Europe, a few locations in North Africa.
Habitat: Grows in moist, saline areas, mainly in coastal areas, such as seashore meadows; or very scattered in inland localities under saline or rarely fresh water conditions. It is rarely found in ruderal areas. The species occurs at low altitudes (< 500 m), but in North Africa between 1000 and 2100 m.
Status and frequency: H. secalinum was formerly abundant in inland localities in Europe, but is now rare due to urbanization and expansion of cultivation. Thus, the common use of fertilizers and drainage have changed rather poor grasslands into lush pastures. For similar reasons, the coastal populations are decreasing.
Chromosome number: Tetraploid, 2n = 28.
Variation: H. secalinum shows comparatively little morphological variation. Material from northern Europe, needs a comparatively long vernalization period, whereas southern material flowers easily without vernalization. Spanish plants have considerably longer awns and glumes than material from other areas.
Morphologically similar species: Small forms of H. secalinum have often been mis-identified as H. marinum. There is a certain morphological resemblance to H. capense from southern Africa, to H. brachyantherum from western North America, and to H. parodii from South America.
Notes: Most of the short-awned, perennial Hordeum species have at one time or another been referred to as H. secalinum. Several varieties have been described. H. secalinum is an alloploid with genomes basically similar to those of H. capense.
Synonyms: H. nodosum auct., non L., H. pratense Huds., H. maritimum O.F. Müller, Critesion secalinum (Schreb.) A. Löve.
References: Bothmer and Jacobsen (1980), Baum and Bailey (1989b).
Morphology: Plants up to 70 cm tall, in dense tufts. Culms erect, usually rather robust; nodes glabrous. Leaves flat or with involute margins, scabrid or rather densely hairy with long hairs; auricles lacking on the uppermost leaves, sometimes present on the basal ones, and up to 0.8 mm long. Spikes 45-80 mm long, greyish-green; glumes and lemma awns pale purple. Central spikelets sessile, glumes 13-23 mm long, setaceous to more or less flattened in the basal part, spreading in the fruiting stage; lemma glabrous, awn of lemma 10-22 mm long; anthers 1.8-4.0 mm long, yellow to purple. Lateral spikelets often developed and male.
Life form and reproduction: Perennial, mainly inbreeding.
Distribution: Republic of South Africa and Lesotho, mainly in highland areas.
Habitat: The species occurs on fertile soil in wet places like river banks and mountain meadows, rarely as a garden weed. It grows up to 2700 m, and withstands heavy grazing.
Status and frequency: H. capense is probably rather common in its distribution area, but no field study has been made.
Chromosome number: Tetraploid, 2n = 28
Variation: The species shows large variation, especially in quantitative characters, like length of palea, glumes, and lemma awns. Considerable variation is also found in the pubescence of vegetative parts.
Morphologically similar species: H. capense is fairly similar to H. secalinum and to some forms of the South American H. parodii and H. fuegianum.
Notes: H. capense was considered by several authors to be conspecific with H. secalinum and to have been introduced to southern Africa by the first European settlers. However, it has been shown to be a distinct species, but related to the European H. secalinum.
Synonyms: Critesion capense (Thunb.) A. Löve.
References: Bothmer and Jacobsen (1980), Baum and Bailey (1989b).
Morphology: Plants up to 1 m tall, but usually 30-80 cm. Culms ascending or geniculate, rather robust; nodes densely pubescent. Leaves flat with a scabrid or pubescent surface; auricles lacking. Spikes 35-90 mm long, pale whitish glaucous, greenish to dark greenish violet; rachis tough or brittle only in its upper parts. Central spikelet sessile, glumes 5-10 mm long, setaceous; lemma pubescent in the upper half or only at the apex, glabrous in the lower part, awn of lemma 5-11 mm long, of the same length or longer than the body of the lemma; rachilla 4.5-7.5 mm long, of the same length or slightly shorter than the palea; anthers 1.5-2.5 mm long, yellow or violet. Lateral spikelets usually well-developed, perfect, and often seed setting, glumes setaceous.
Life form and reproduction: Perennial, inbreeding, but some outbreeding probably occurs.
Distribution: In Central Asia, western Iran, Afghanistan, northern and western Pakistan, northern India, southern Siberia, Mongolia, and northern China.
Habitat: H. bogdanii usually grows in saline areas, like shores of lakes, streams, and ponds, and in meadows. Apart from these habitats it occurs in wet places with fresh water, on limestone cliffs, and rarely as a weed. It occurs at altitudes from 1000 to 3800 m.
Status and frequency: The species is common wherever suitable habitats are available.
Chromosome number: Diploid, 2n = 14.
Variation: H. bogdanii is rather invariable, but shows some geographical differentiation, e.g. Russian material is generally taller, stouter, and has broader leaves than plants from other areas. Most populations of the species have a tough rachis, especially in the lower part, but in some populations it is more brittle.
Morphologically similar species: H. bogdanii is a quite distinct species and it is usually not misidentified. However, small and violet tinged specimens may resemble H. brevisubulatum subsp. turkestanicum somewhat.
Synonyms: Before the description of the species (1918) by Wilensky, H. bogdanii was known under the names H. nodosum and H. pratense, both of which are illegitimate names for H. secalinum, Critesion bogdanii (Wil.) A. Löve.
References: Bothmer (1979), Yang et al. (1987).
Morphology: Plants 30-85 cm, caespitose in rather loose tufts. Culms erect and slender; nodes glabrous usually short and dark. Leaves flat, scabrid or glabrous; auricles usually lacking, when present up to 1.6 mm long. Spikes 30-60 mm long, pale green to dark greenish violet with a very brittle rachis at maturity. Central spikelet sessile, glumes 6-10 mm long, setaceous, spreading at maturity, usually longer than the paleas; lemma glabrous, awn of lemma 4-8 mm long and longer than the lemma body; anthers 1-1.7 mm long, yellow. Lateral spikelets rudimentary, rarely male.
Life form and reproduction: Perennial and mainly inbreeding.
Distribution: Southern Siberia, Mongolia, North-Central China
Habitat: The species is mainly found in moist areas like shores of lakes and streams, saline meadows, pebble beds, and sometimes along roads and field edges. It does not occur in such extreme saline environments as H. bogdanii.
Status and frequency: H. roshevitzii is a rather common species in its distribution area.
Chromosome number: Diploid, 2n = 14. An earlier report about one tetraploid Siberian population is not correct (cf. Bothmer 1979).
Variation: The lateral spikelets of H. roshevitzii are usually very rudimentary, but in some populations from Siberia they are well developed and male. Some populations from northern China have pubescent lemmas and culm nodes, which may merit taxonomic recognition.
Morphologically similar species: H. roshevitzii is a morphologically distinct species, but may resemble short-awned forms of H. brachyantherum.
Notes: Material of the species was formerly wrongly determined as H. bogdanii and H. brevisubulatum, which gave the erroneous impression that H. roshevitzii is a rare species. The name H. violaceum has sometimes erroneously been used for this species.
Synonyms: The species was first named H. sibiricum by Roshevitz (1929), which, however, was an illegitime name. In older literature the names H. nodosum and H. pratense were used for H. roshevitzii. Critesion californicum (Covas & Stebbins) A. Löve subsp. sibiricum A. Löve.
References: Bothmer (1979), Yang et al. (1987).
Morphology: Plants 20-90 cm tall, caespitose, growing in rather dense tufts, often with short or long subterranean runners. Culms erect, nodes glabrous or pubescent Leaves flat or with involute margins, surface scabrid to glabrous on the abaxial side; auricles present or lacking, when present 0.5-2 mm long. Spikes 30-90 mm long, whitish green to greyish violet. Central spikelet sessile (rarely subsessile), glumes 4-10 mm long, setaceous; lemma glabrous to densely covered with long hairs, awn of lemma short, 1-6 mm long, rarely lacking; anthers 2.5-5 mm long, yellow to purple. Lateral spikelets usually developed and male, sometimes rudimentary; lemma aristate with awn up to 2.5 mm, rarely awnless.
Life form and reproduction: Perennial, sometimes with vegetative dispersal; obligate outcrosser with a self-incompatibility system, which means that seed set is often low in nature.
Distribution: From western Turkey to northeastern China (see under the subspecies).
Habitat: See under the subspecies.
Status and frequency: The species is common in the distribution area where suitable habitats are present.
Chromosome number: Diploid, tetraploid, and hexaploid, 2n = 14, 28, 42.
Variation: H. brevisubulatum is a very variable species, which is illustrated by the fact that several taxa (now treated as subspecies) are recognized.
Morphologically similar species: Some forms of H. roshevitzii and H. bogdanii may look similar to H. brevisubulatum.
Notes: H. brevisubulatum is a polyploid complex of autoploids in which the different forms are recognized as subspecies. In areas where the subspecies overlap, hybridization and introgression occur and there may be intermediate or transitional forms; in these areas (see map) the material can be very difficult to identify to subspecies.
Synonyms: Within the H. brevisubulatum complex several taxa have been described. The most common ones are given under the subspecies.
References: Bothmer (1979), Dewey (1979), Landström et al. (1984), Yang et al. (1987).
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1. Culm nodes hairy |
2 |
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1. Culm nodes glabrous |
4 |
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2. Glumes of central spikelets more than 7 mm and awns of
lemma more than 3 mm |
subsp. iranicum |
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2. Glumes of central spikelets less than 7 mm and awns of
lemma less than 3 mm |
3 |
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3. Lemma with long, dense, often curled hairs |
subsp. turkestanicum |
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3. Lemma with short, straight, and more sparse hairs |
subsp. nevskianum |
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4. Glumes of central spikelets longer than the palea and more
than 7 mm |
subsp. violaceum |
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4. Glumes of central spikelets shorter or of the same length
as the palea and less than 7 mm |
subsp. brevisubulatum |
subsp. brevisubulatum
Morphology: Glabrous culm nodes and lemmas. The glumes of the central spikelet are short, usually less than 7 mm long. Lemma awns are short, less than 3 mm. The walls of the epidermal long cells are thin and straight and lack silica bodies.
Distribution: Subsp. brevisubulatum occurs in southeastern Siberia, Mongolia, and northern China.
Habitat: It grows in saline meadows, on the banks of streams with fresh water, and in steppe valleys up to the timber line. It occurs at altitudes of 1400-3000 m.
Chromosome number: Diploid and tetraploid, 2n = 14, 28.
Variation: Most specimens of subsp. brevisubulatum have glabrous lemmas, but forms with short hairs are found, especially in north-eastern China; length of glumes may also vary.
Synonyms: H. macilentum Steud., Critesion brevisubulatum (Trin.) A. Löve.
subsp. nevskianum (Bowden) Tzvelev
Morphology: Subsp. nevskianum has short glumes on the central spikelets (usually <6.5 mm) and short lemma awns (<3 mm); the spikes are rather long and pale glaucous. The lemmas are normally pubescent, but the hairs are shorter and more sparse than in subsp. turkestanicum; culm nodes are also pubescent.
Distribution: Nepal, northern Kashmir in India and Chitral in Pakistan, westernmost China, western Siberia and northeastern Afghanistan.
Habitat: Subsp. nevskianum usually grows in saline meadows or in salt steppes, but also in wet meadows with fresh water, in dry valleys, and rarely as a weed. It occurs from 1500 to 5000 m.
Chromosome number: Diploid and tetraploid cytotypes occur, 2n = 14, 28.
Variation: In the region where subsp. nevskianum and subsp. turkestanicum meet in Pamir and northern Kashmir, intermediate types are present. In other areas subsp. nevskianum is rather invariable.
Synonyms: H. nevskianum Bowden; H. secalinum Schreb. var. brevisetaceum O. Kuntze, Critesion brevisubulatum (Trin.) A. Löve subsp. nevskianum (Bowden) A. Löve.
subsp. turkestanicum (Nevski) Tzvelev
Morphology: Subsp. turkestanicum is usually a rather small plant (up to 50 cm) with dense spikes, greyish violet in colour and with a dense pubescence of the lemma; culm nodes hairy; it has long lemma awns of central spikelets, but often lacks an awn on the lateral spikelets.
Distribution: Occurs in a rather restricted area, comprising central and northeastern Afghanistan, Chitral in Pakistan, south Tadzjikistan, and westernmost China (province of Xinjiang).
Habitat: It is most frequent in rather dry areas, for example dry, stony slopes, but rarely also on banks of streams and meadows, probably not in too saline habitats; it grows at altitudes of 2000-4600 m.
Chromosome number: Tetraploid and hexaploid, 2n = 28, 42.
Variation: It shows great variation in pubescence and also in length of lemma awns.
Synonyms: H. turkestanicum Nevski, Critesion brevisubulatum (Trin.) A. Löve subsp. turkestanicum (Nevski) A. Löve.
subsp. violaceum (Boissier & Hohenacker) Tzvelev
Morphology: In subsp. violaceum the glumes are longer than 7 mm, often 9-10 mm long; lemma awns are >3 mm, usually up to 4.5 mm or more; lemma and culm nodes are usually glabrous; spikes are violet or greenish violet.
Distribution: Central Turkey, Caucasus, the northern parts of western and eastern Azarbaijan in Iran, and the Alborz Mountains where subsp. violaceum and subsp. iranicum overlap.
Habitat: Subsp. violaceum grows in wet meadows and by small streams in the montane zone up to ca. 3500 m; rarely in saline biotopes near canals, and in disturbed habitats.
Chromosome number: Diploids, 2n = 14, and a few tetraploids, 2n = 28, occur.
Variation: Subsp. violaceum has a rather limited range of variation; some samples from eastern Turkey (Erzurum) differ by densely hairy lemmas and culm nodes.
Notes: The taxon is confined to the western part of the distribution area of the species. Reports in floras from other areas are wrong determinations referring to other subspecies. In Chinese literature the name H. violaceum is used for H. roshevitzii.
Synonyms: H. violaceum Boiss. & Hohen., Critesion violaceum (Boiss. & Hohen.) A. Löve.
subsp. iranicum Bothmer
Morphology: Subsp. iranicum is usually a tall and robust plant; culm nodes are pubescent, but the lemmas are usually glabrous. Glumes > 7 mm, usually 8-10 mm. Awns of central spikelets are more than 3 mm, often up to 4.5 mm or even longer.
Distribution: Western and southern Iran in the Zagros and the Alborz mountains; in the latter area it has an overlapping distribution with subsp. violaceum.
Habitat: Usually in meadows and along streams in saline water, and rarely on ground with more or less fresh water. It occurs in altitudes up to ca. 3500 m.
Chromosome number: Hexaploids, 2n = 42, and a few tetraploid populations, 2n = 28.
Variation: In the Zagros mountains in western Iran there is a certain variation in the pubescence of the lemma, length of glumes and lemma awns; and in the Alborz transitional forms to subsp. violaceum and subsp. nevskianum occur.
Synonyms: Material of subsp. iranicum was formerly treated under H. violaceum, Critesion iranicum (Bothmer) A. Löve.
Morphology: Plants in loose to dense tufts, 25-90 cm tall. Culms slender to stout, erect or geniculate; nodes glabrous. Leaves flat or rarely with involute margins, glabrous to densely pubescent; auricles lacking. Spikes 30-85 mm long, green to purplish green. Central spikelet sessile, glumes 7-18 mm long, setaceous or rarely flattened at the base; lemma glabrous or rarely pubescent, awn of lemma 4-13 mm; anthers 0.8-3.5 mm, yellow to violet. Lateral spikelets rudimentary or male fertile or rarely perfect and seed setting, lemma muticous, acute or aristulate, with awns up to 6 mm.
Life form and reproduction: Perennial and mainly inbreeding, but some outbreeding populations occur.
Distribution: Western North America, from Baja California in Mexico northwards to Alaska and the Aleutian islands to the Kamtchatka peninsula in Russia and a few populations on the Curillic islands. In the USA it extends eastwards to the states of Idaho, Utah, Wyoming, and Colorado. A small disjunct distribution occurs in the northern parts of Newfoundland and adjacent Labrador in eastern Canada.
Habitat: The species occurs in salt marshes, pastures, woodlands, and subalpine meadows up to 4000 m in southwestern USA to subarctic woodland meadows in western Canada, Kamtchatka, and Alaska.
Status and frequency: In its distribution area it is a very common species. It can produce large stands and be a dominant grass in the pastures.
Chromosome number: Diploid, and tetraploid. One single hexaploid population is known, 2n = 14 (subsp. californicum), 28, 42 (subsp. brachyantherum).
Variation: The species is very variable especially in length of glumes and awns; these can be straight or deflexed in the fruiting stage. Length of culms, pubescence, and colour of spikes are other variable characters.
Morphologically similar species: Due to the large variation amplitude of H. brachyantherum, many species may be similar to it, e.g. H. roshevitzii, H. depressum, H. parodii, H. tetraploidum, some forms of H. secalinum, and H. capense.
Notes: The diploid form, occurring only in a limited area in central California in the USA was described as a separate species, H. californicum Covas & Stebbins, which was claimed to have, e.g. awned lemmas of lateral spikelets. The tetraploids from California have muticous lemmas (or rarely very short awns), but tetraploids from Utah and Nevada may have awns also on the lateral spikelets. There are also large overlaps in other morphological characters, why an unambiguous delimitation between them is not possible. We prefer to keep the diploid and the tetraploid cytotypes as subspecies. The hexaploid was found as a single population in California and until further investigations have been made we maintain the hexaploid also in subsp. brachyantherum. In areas where H. brachyantherum and H. jubatum have overlapping distribution areas they may occur together and hybrid swarms are not uncommon.
Hordeum brachyantherum subsp. brachyantherum 4x
References: Bowden (1962), Baum & Bailey (1989a), Bothmer et al. (1988b, 1991, 1993), Bothmer & Jacobsen (1989b).
Key to the subspecies of H. brachyantherum:
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1. Plants usually robust; leaves up to 8 mm broad, glabrous to
sparsely pubescent with short hairs; anthers up to 3 mm |
subsp. brachyantherum |
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1. Plants slender; leaves narrow up to 3 mm broad; usually
densely pubescent with long hairs; anthers up to 4 mm |
subsp. californicum |
Morphology: Plants usually robust, and with tall culms (30-95 cm), densely tufted; leaf sheaths glabrous or sparsely pubescent; leaves usually broad (up to 8 mm) glabrous or with short adpressed hairs. Glumes and awns are usually straight in the fruiting stage; anthers often short (<2.5 mm).
Distribution: See under the species.
Synonyms: H. nodosum auct. non L., H. boreale Scribn. & Sm., H. jubatum L. subsp. breviaristatum Bowden, Critesion jubatum (L.) Nevski subsp. breviaristatum (Bowden) A. & D. Löve.
subsp. californicum (Covas & Stebbins) Bothmer, Jacobsen & Seberg
Morphology: Plants slender, usually short culms (20-65 cm), loosely tufted; leaf sheaths densely pubescent; leaves narrow usually <3 mm with long spreading hairs. Glumes and awns are usually spreading in the fruiting stage; anthers up to 4 mm.
Distribution: It is endemic to southwestern California up to north of the Bay area. Its distribution overlaps with that of subsp. brachyantherum, and in a few locations they grow together.
Synonyms: H. californicum Covas & Stebbins, Critesion californicum (Covas & Stebbins) A. Löve subsp. californicum, H. brachyantherum Nevski var. gracilis Nevski.
Hordeum brachyantherum subsp. brachyantherum 4x
Hordeum brachyantherum subsp. californicum 2x
Hordeum brachyantherum subsp. brachyantherum 6x
Morphology: Plants 10-55 cm tall, in loose tufts. Culms slender, erect or somewhat geniculate; nodes glabrous; the spikes sometimes mature halfway up in the uppermost leaf sheath. Leaves flat or rarely with involute margins, abaxial surface sparsely to densely pubescent, rarely glabrous; auricles lacking. Spikes 20-70 mm long, pale green or glumes and lemma awns with a reddish tinge. Central spikelet sessile (rarely subsessile), glumes 5.5-20.5 mm long, setaceous or somewhat flattened at base, lemma glabrous, awn of lemma 3-12 mm; anthers 0.6-1.3 mm, usually yellow. Lateral spikelets rudimentary, rarely male, awn of lemma usually lacking, when present up to 1 mm; upper glume setaceous, lower glume somewhat flattened at base.
Life form and reproduction: Annual and inbreeding.
Distribution: The species occurs in western USA. Its centre of distribution is central California, but a few locations in the states of Oregon and Washington are known.
Habitat: The original habitats are saline areas and vernal pools, but it may occur close to agriculture in ditches and canals.
Status and frequency: H. depressum is scattered in the central and southern Californian area where suitable habitats occur.
Chromosome number: Tetraploid, 2n = 28.
Variation: There is some variation in height, length of glumes, and thickness of the spike.
Morphologically similar species: Young specimens of H. marinum subsp. gussoneanum and H. brachyantherum may resemble H. depressum.
Notes: H. depressum has been considered to be of allotetraploid origin, but recent investigations indicate that it may be a segmental alloploid or even of autoploid nature (Petersen 1991b).
Synonyms: H. nodosum L. var. depressum Scribn. & Sm., Critesion depressum (Scribn. & Sm.) A. Löve.
References: Bowden (1962), Baum & Bailey (1988), Bothmer et al. (1988b), Bothmer & Jacobsen (1989b).
Morphology: Plants coarse, also with sterile shoots, up to 55 cm tall, loosely caespitose to somewhat rhizomatous. Culms erect to somewhat geniculate; nodes glabrous. Leaves flat, sparsely scabrid; auricles lacking. Spikes 20-40 mm long, greenish to dark purple. Central spikelet sessile to subsessile, glumes 5-8 mm long, setaceous to somewhat flattened at the base; lemma glabrous to somewhat scabrid hairy at the apex, awn of lemma 2.5-5.5 mm long; anthers 1.5-2 mm long, yellow to somewhat violet. Lateral spikelets mostly rudimentary, acuminate; upper glume setaceous, lower glume setaceous to somewhat flattened at the base.
Life form and reproduction: Perennial, probably inbreeding.
Distribution: The mountain region of Cuchumatanes in northern Guatemala, 3000-3500 m.
Habitat: In marshy meadows or along streams, often temporarily submerged, apparently reflected in the somewhat rhizomatous habit.
Status and frequency: Known only from a few locations in the Cuchumatanes. The information available suggests that it can be found in other places and that it may not be rare in the area. However, there is heavy sheep grazing in the area and an investigation of its status is needed before any conclusions can be drawn.
Chromosome number: Tetraploid, 2n = 28.
Variation: With the limited material available, little is known of the variation, but there is some variation in the intensity of coloration of the spikes as well as in the fertility of the lateral spikelets.
Morphologically similar species: H. brachyantherum (North America), H. fuegianum, H. tetraploidum, and H. parodii (all South America).
Notes: H. guatemaleuse is a newly described species (1985) that only lately has been available for crossing experiments (Bothmer & Jacobsen 1989a); formerly it was referred to as H. brachyantherum. The species is a segmental alloploid.
References: Bothmer et al. (1985a), Bothmer & Jacobsen (1989a).
Morphology: Plants in dense tufts, up to 80 cm tall. Culms and leaves erect, slender, conspicuously glaucous. Leaves flat or somewhat involute, relatively densely pubescent. Spikes 40-50 mm long, glaucous or pale green, laterally compressed. Central spikelet sessile, glumes 9-11 mm long, setaceous to somewhat flattened; lemma glabrous in the basal part, sparsely pubescent in the upper part, awn of lemma 8-11 mm long; anthers 2-3 mm long, yellow and somewhat violet spotted. Lateral spikelets more or less rudimentary, acuminate; upper glume setaceous, lower glume somewhat flattened at the base.
Life form and reproduction: Perennial, probably mainly inbreeding.
Distribution: Known only from a single locality in the western part of the province of Buenos Aires, Argentina.
Habitat: In halophytic vegetation near a salt lake, at rather low altitude.
Status and frequency: The species is probably more widespread than indicated above, but more information is needed to ascertain its status and frequency.
Chromosome number: Diploid, 2n = 14.
Morphologically similar species: Small forms of H. parodii and H. tetraploidum may resemble H. erectifolium, but these species are purplish in the spikes, are never glaucous, and have never erect leaves.
Notes: H. erectifolium is a very distinct species, not obviously related to any of the other diploid South American species. Despite the fact that the province of Buenos Aires in Argentina is fairly well explored, the species is not represented in any of the major herbaria.
References: Bothmer et al. (1985a).
Morphology: Plants up to 80 cm tall, caespitose, growing in dense or loose tufts, sometimes with short, subterranean runners. Culms erect; older basal sheaths fibrous or membranaceous; nodes glabrous. Leaves flat, surface glabrous to sparsely scabrid hairy on the abaxial side; auricles lacking. Spikes 40-80 mm long, pale green, or greyish to greenish purple. Central spikelet sessile, glumes 4.5-9 mm long, usually setaceous not spreading in the fruiting stage; lemma glabrous or rarely pubescent, awn of lemma 1.5-5.5 mm long; anthers 3-5 mm long, yellow or purple. Lateral spikelets rudimentary or well-developed and male fertile, rarely perfect; lemma muticous or rarely aristulate, awn up to 1.5 mm.
Life form and reproduction: Perennial, probably with a versatile reproductive system, but predominantly outbreeding.
Distribution: H. tetraploidum occurs from the province of Mendoza to the province of Santa Cruz in Argentina. It is more or less sympatric with H. parodii.
Habitat: The species grows in wet or dry pastures, along streams, and on the shores of lakes and ponds, at altitudes up to 1500 m.
Status and frequency: In the central parts of its distribution area, i.e. the western parts of the provinces of Neuquen and Rio Negro, the species is fairly abundant. It is less common than H. parodii.
Chromosome number: Tetraploid, 2n = 28.
Variation: The variation pattern is rather complex with transitional forms to H. parodii, with which it overlaps in several morphological traits. The best distinguishing characters between H. tetraploidum and H. parodii is the generally longer anthers in the former, usually longer than 3.0 mm. Most material has glabrous lemmas, but hairy lemmas occur in plants from the southern part of the Neuquen province. The glumes are usually setaceous, but some populations may have more or less flattened basal parts of the glumes.
Morphologically similar species: Large forms of H. tetraploidum may resemble H. parodii and forms of H. fuegianum without spreading glumes.
Notes: H. tetraploidum is a segmental allotetraploid. The three species H. parodii, H. tetraploidum, and H. fuegianum constitute a polyploid complex. They are closely related, and share common genomes.
Synonyms: Critesion tetraploidum (Covas) A. Löve. References: Covas (1953), Bothmer et al. (1986c).
Morphology: Plants 20-50 cm, densely caespitose. Culms coarse, geniculate or erect; older basal sheaths densely fibrous; nodes glabrous. Leaves flat, abaxial leaf surface sparsely to densely pubescent; auricles lacking. Spikes 40-70 mm long, greenish to greyish violet. Central spikelets sessile to subsessile, glumes 10-15.5 mm long, setaceous to somewhat flattened in the basal part, usually spreading in the fruiting stage; lemma glabrous to more or less sparse with long, scabrid hairs, awn of lemma 4-8 (-14) mm long; anthers 1.5-2 mm long, yellow or violet. Lateral spikelets rudimentary or well-developed and male fertile, lemma muticous to aristulate at apex, awns up to 1.5 mm long.
Life form and reproduction: Perennial, mainly inbreeding.
Distribution: Tierra del Fuego, and a few locations in the region of Magellanes in southern Chile.
Habitat: H. fuegianum is found in meadows and grasslands, often in riverbeds, also near the sea. It grows near both fresh and somewhat saline water, only at lower altitudes (<100m).
Status and frequency: The species is common in its area of distribution. Chromosome number: Tetraploid, 2n = 28.
Variation: H. fuegianum is a rather invariable plant. It is a low, usually coarse plant. Most populations have distinctly spreading glumes at maturity, but in a few populations they are straight. Lemmas are usually glabrous, but a few populations have sparsely hairy lemmas.
Morphologically similar species: Slender forms of H. fuegianum resemble H. parodii and H. tetraploidum.
Notes: H. fuegianum is a segmental allotetraploid. It is closely related to H. tetraploidum and the hexaploid H. parodii and has basically the same genomes as these species.
References: Hunziker & Itria (1980), Bothmer et al. (1986c).
Morphology: Plants up 100 cm, growing in dense tufts rarely with short runners. Culms slender to coarse; older basal sheaths usually fibrous; nodes glabrous. Leaves flat, abaxial leaf surface glabrous, scabrid or rarely with sparse hairs; auricles lacking. Spikes 45-100 mm long, pale or greyish green to pale greyish violet. Central spikelet sessile to subsessile, glumes 7-15 mm long, setaceous, rarely somewhat flattened in the basal part, usually erect in the fruiting stage; lemma glabrous to somewhat scabrid hairy at the apex or rarely densely pubescent, awn of lemma 1.5-8 mm long; anthers 1.3-3 mm long, yellow or purple. Lateral spikelets rudimentary or well-developed and male fertile, rarely perfect, lemma muticous to aristulate at apex (awn up to 0.8 mm).
Life form and reproduction: Perennial, probably predominantly inbreeding.
Distribution: H. parodii occurs from the northern part of the province of Mendoza southwards to the province of Santa Cruz in Argentina. There are a few scattered localities in the province of Buenos Aires, in the region of Magellanes in south Chile, and on the Chilean side of Tierra del Fuego.
Habitat: The species is found in humid habitats, such as grassy or sandy riverbanks and canals, and wet pastures. It is found near both fresh and saline water at altitudes up to 1000 m.
Status and frequency: H. parodii is a fairly common plant in the central parts of its distribution area wherever suitable habitats are present.
Chromosome number: Hexaploid, 2n = 42.
Variation: The species is very variable, e.g. in size of glumes, hairiness of lemma; glumes are usually setaceous, but are sometimes flattened in the basal parts; lateral spikelets are sometimes well-developed.
Morphologically similar species: Because of overlap in many morphological characters H. parodii and H. tetraploidum may be difficult to separate. There are also resemblances to the Asiatic H. brevisubulatum sensu lato.
Notes: The name H. brachyatherum Philippi (not H. brachyantherum Nevski) has often been used for large specimens of H. parodii. The name H. brachyatherum refers to the intergeneric hybrid between Elymus spp. and H. parodii as shown by the type material. H. parodii forms a polyploid complex with H. tetraploidum and H. fuegianum. It is a segmental allohexaploid.
Synonyms: H. parodii Covas var. araucanum Parodi & Nicora, Critesion parodii (Covas) A. Löve.
References: Covas (1951, 1953), Hunziker et al. (1975), Bothmer et al. (1986c).
Morphology: Plants in small or large, dense tufts with few or many culms. Culms slender, erect to procumbent; nodes glabrous, sometimes with spikes mature halfway up in the uppermost leaf sheath, especially in small specimens from saline habitats. Leaves flat or involute, more or less glabrous to densely pubescent; auricles lacking. Spikes 12-45 mm long, pale green to dark purple. Central spikelet sessile, glumes 5-11 mm long, setaceous to more or less flattened at the base; lemma glabrous to densely pubescent, awn of lemma up to 6 mm long; anthers 0.8-2.5 mm long, yellow to violet. Lateral spikelets usually rudimentary; upper glume setaceous, lower glume setaceous or flattened at the base.
Life form and reproduction: Perennial, inbreeding or rarely open-pollinated. Distribution: Southern South America, Chile and Argentina to Tierra del Fuego.
Habitat: Seaside localities, saltpans, salty areas around lakes and along rivers in seasonally inundated places; sometimes the habitats are somewhat disturbed by grazing, at low altitude (<300 m).
Status and frequency: The different subspecies are all rather common within their area although they are usually not a dominant element in the plant associations. The small size of the plants also contributes to their being overlooked. Only subsp. mustersii, known from only two localities, may be threatened if its rather special habitat is disturbed. The other subspecies do not seem to be affected by some habitat disturbance.
Chromosome number: Diploid, 2n = 14.
Variation: The species shows a very wide range of variation mainly reflected in the description of five subspecies.
Morphologically similar species: Small specimens of H. parodii and H. tetraploidum.
Notes: The various subspecies were previously regarded as separate species, but hybridization experiments have shown them to be closely related. Frequent interbreeding probably occurs in nature.
References: Covas (1953), Nicora (1977), Parodi & Nicora (1977), Bothmer et al. (1986b, 1988c).
Hordeum patagonicum subsp. Patagonicum
Key to the subspecies of H. patagonicum
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1. Glumes and leaves more or less flat |
2 |
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2. Glumes and lemma distinctly pubescent; culm erect, spike
sometimes nodding; inland plants |
subsp. mustersii |
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2. Glumes and lemma glabrous; culm often nodding, with a
pendant to procumbent spike; inland or seaside plants |
subsp. magellanicum |
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1. Glumes setaceous, leaves setaceous to involute |
3 |
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3. Lemma usually pubescent or distinctly scabrid; glumes of
about the same length as the central spikelet or shorter; culm erect; spike not
distinctly compressed |
subsp. patagonicum |
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3. Lemma glabrous or indistinctly scabrid only in the upper
part; glumes shorter than the central spikelet; culm (erect to) somewhat nodding
to procumbent; spike compressed or not distinctly compressed |
4 |
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4. Lateral spikelets about the length of the body of the
lemma; plants usually more than 15 cm high; leaves more than 5 cm long; culm
erect, spike erect to somewhat nodding, not distinctly compressed |
subsp. setifolium |
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4. Lateral spikelets about half the length of the body of the
lemma; plants usually less than 15 cm high; leaves less than 5 cm long; culm
pendent to procumbent; spike dark purple, distinctly compressed |
subsp. Santacrucense |
Morphology: Plants erect, densely tufted, usually less than 12 cm tall. Leaves more or less involute, less than 2.5 cm long. Spikes green to pale greenish violet, less than 45 mm long. Lemma of central spikelet sparsely to densely pubescent in more than the upper third, awn 2.5-5.5 mm long, glumes more or less spreading; anthers 1.1-1.7 mm.
Distribution: Southernmost part of the province of Chubut and along the coast of the province of Santa Cruz.
Synonyms: H. patagonicum (Haum.) Covas, Critesion patagonicum (Haum.) A. Löve.
subsp. setifolium (Parodi & Nicora) Bothmer, Giles & Jacobsen
Morphology: Plants erect, tufted, up to 40 cm tall. Leaves involute, up to 10 cm long. Spikes green to pale greenish violet or more often dark violet, up to 55 mm long. Lemma of central spikelet glabrous or almost so, awn up to 6.5 mm long, glumes more or less spreading; anthers up to 2.5 mm long.
Distribution: Western part of the province of Chubut to NW part of the province of Santa Cruz.
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subsp. santacrucense (Parodi & Nicora) Bothmer, Giles & Jacobsen
Morphology: Plants tufted, erect to somewhat nodding, after flowering with decumbent culms, less than 20 cm long. Leaves involute, up to 2.5 cm long. Spikes dark purple, somewhat compressed, up to 2.5 cm long. Lemma of central spikelet usually glabrous, awn up to 4 mm long, glumes not spreading; anthers 0.8-1.5 mm long.
Distribution: Southern part of the province of Santa Cruz, southwards to the Strait of Magellan.
Synonyms: H. santacrucense Parodi & Nicora, Critesion santacrucense (Parodi & Nicora) A. Löve.
subsp. musters/7 (Nicora) Bothmer, Giles & Jacobsen
Morphology: Plants erect, tufts slender, culms up to 30 cm long. Leaves flat, sometimes involute, up to 6.5 cm long. Spikes slender, greenish with a purple tinge, up to 30 mm long. Lemma of central spikelet with a dense indumentum, awn up to 1 mm long, glumes not spreading; anthers up to 1.2 mm long.
Distribution: Known from two localities in the province of Santa Cruz.
Synonyms: H. mustersii Nicora, Critesion mustersii (Nicora) A. Löve.
subsp. magellanicum (Parodi & Nicora) Bothmer, Giles & Jacobsen
Morphology: Plants slender, in small to stout tufts, sometimes with short, subterranean stolons, culms up to 45 cm. Leaves usually flat, up to 5 cm long. Spikes rather lax, often nodding, usually pale, glaucous green, rarely purplish tinged, 40 (inland) to 70 (coastal) mm long. Lemma of central spikelet sometimes sparsely pubescent in the upper quarter, awn of lemma up to 2 mm long, glumes somewhat spreading; anthers 0.8-1.6 mm long. Lateral spikelets sometimes more or less fertile.
Distribution: From southernmost Patagonia with several inland localities to Tierra del Fuego in mostly seaside localities.
Synonyms: H. chilense Roem. & Schult. var. magellanicum Parodi & Nicora, Critesion magellanicum (Parodi & Nicora) A. Löve.
