GENERA OF NORTH AMERICAN FABACEAE III. TRIBE PSORALEAE

Both Bentham and Hooker, and Taubert, admit that these characters do not absolutely distinguish the genera of this subtribe from all other genera of Fabaceae, for I-seeded indehiscent pods are found elsewhere in the family and glandular-dotted plants are also found, as Glycyrrhiza. They have, however, overlooked the fact that several of the species by them included in Psoralea have dehiscent pods. This is the case with all those segregated by me as the genus Pediomelum. I also suspect that in the genus Hoita, judging from the texture and structure, the pod also is tardily dehiscent. If so it is valvate, not circumscissile as in Pediomelum. Though there remains not a single character that absolutely distinguishes the genera of this tribe from all others in the family, the group is rather natural and in my opinion it should be regarded as a tribe rather than a subtribe of Galegeae. It shows, for instance, just as much affinity to Hedysareae or Trifolieae, in which tribes I-seeded indehiscent pods are found. In Cullen (a segregate from Psoralea), the leaflets are toothed and the pod much like that found in the latter tribe, while in Asphalthium the pod is practically a loment of 2 internodes, the lower closely investing the seed and the upper (the beak) empty and breaking off. The tribe shows many variations, and the genera show more abnormalities than in any other tribe as far as I know. The tribe includes herbs, shrubs, and trees, usually with gland-dotted foliage. In some cases the gland-dots are confined to the calyx or fruit alone. In one case, Or