TABLE OF CONTENTS ACKNOWLEDGEMENTS INTRODUCTION    Position and delimitation of Hordeum    Species concepts - delimitation and determination of species    Previous taxonomic studies    Morphology and terminology    Distribution    Ecology    Biology, reproduction, life forms, and dispersal    Genome relationships in Hordeum    Protein relationships in Hordeum    Variation in chromosome numbers and karyotypes    Genetic resources in Hordeum KEY TO THE SPECIES OF HORDEUM DESCRIPTIONS OF THE SPECIES    Section Hordeum       Hordeum vulgare L.       Hordeum bulbosum L.       Hordeum murinum L.    Section Anisolepis       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    Section Critesion       Hordeum pubiflorum Hooker f.       Hordeum halophilum Grisebach       Hordeum comosum Presl       Hordeum jubatum L.       Hordeum arizonicum Covas       Hordeum procerum Nevski       Hordeum lechleri (Steudel) Schenck    Section Stenostachys       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 ILLUSTRATIONS OF THE GLUMES IN THE SPECIES OF HORDEUM REFERENCES INDEX