The Bignoniaceae comprise more than 600 species of trees, shrubs, woody vines and, rarely, herbaceous plants in about 100 genera. Cultivated species include Crescentia cujete L. (calabash), the woody shells of the fruits providing domestic utensils, and Parmentiera edulis DC. (cauchilote), the flesh of the fruits being edible. The fruits are large and, usually, dehiscent capsules. Where known, seed storage behaviour is orthodox. For example, seeds of Incarvillea spp. are maintained in the long-term seed store at the Wakehurst Place Gene Bank.
SEED DORMANCY AND GERMINATION
The seeds are usually winged. Seed dormancy does not appear to be a great problem and it appears that most species are easily grown from seed. The information on seed germination provided here is limited to that summarised in Table 25.1, but as a first step in developing suitable germination test procedures RBG Kew Wakehurst Place suggests testing the seeds at a constant temperature of 21°C with light applied for 12h/d.
TABLE 25.1 Summary of germination test recommendations for species within the Bignoniaceae
|
Species and Authority |
Substrate |
Temperature |
Duration |
Additional directions |
Source |
|
Catalpa bignonioides Walt. |
TP |
20°/30°C |
21d |
|
AOSA |
|
Catalpa speciosa Warder |
TP |
20°/30°C |
21d |
|
AOSA |
|
Catalpa spp. |
TP |
20°/30°C |
21d |
|
ISTA |
