Shrubs [trees], unarmed [spinose]. Stems erect, pubescent [glabrous], hairs glandular, fine-appressed to spreading; peduncles and pedicels glandular-hirsute. Leaves alternate, odd-pinnate; stipules present; petiolate; leaflets [13–]19–25[–35], usually alternate, sometimes subopposite, stipels absent, blade margins entire, surfaces glabrous. Inflorescences 4–7-flowered, terminal and axillary, racemes; bracts present; bracteoles present. Flowers papilionaceous; calyx campanulate, tubular basally, lobes 5; corolla usually yellowish; stamens 10, diadelphous; anthers dorsifixed, ± uniform. Fruits legumes, stipitate, slightly inflated [to bladderlike], straight, oblong [lanceoloid-ellipsoid], dehiscent, pubescent. Seeds 4–14, oblong.

Distribution

Arizona, Mexico.

Discussion

Species 19 (1 in the flora).

Most species in Diphysa have inflated, bladderlike fruit segments, reminiscent of Sesbania. The segments in Diphysa thurberi, however, are barely or not at all inflated.

Selected References

None.

Lower Taxa

Diphysa thurberi