Psoralea rydbergii Cory

Pediomelum humile Rydberg, sp. nov
Psoralea esculenia A. Gray, PI. Wright. 2: 37 (erroneously referred). 1853.
A subacaulescent perennial, with a fusiform deep-seated root 4-6 cm. long, 1-3 cm. thick; stem above ground almost none; leaves 3-foliolate with stalked terminal leaflet, clustered at the base; stipules membranous, lanceolate; petioles 3-6 cm. long, strigose; leaflets about 2 cm. long, conspicuously glandular-punctate, strigose beneath and on the veins above, the lateral ones broadly and obliquely ovate, sessile, the terminal one broadly rounded-rhombic or suborbicular, on a rachis about 1 cm. long; peduncles about 4 cm. long, strigose; spikes dense, many-flowered, 2-3 cm. long; calyx strigose; tube about 5 mm. long; lobes linear-subulate, 7-8 mm. long; corolla purplish, 15 mm. long or more; fruit unknown.
Type collected in the valley of Rio Grande near Piedras Nigras, Coahuila, April 19, 1910, Pringle 9205 (U. S. Nat. Herb. no. 381823).
Distribution: Type locality and San Felipe, Texas.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Nodules present, Stems very short, acaulescent or subacaulescent, Stems erect or ascending, Stems less than 1 m tall, Plants gland-dotted or with gland-tipped hairs, Stems solid, Stems or young twigs sparsely to densely hairy, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules setiform, subulate or acicular, Stipules persistent, Stipules free, Leaves compound, Leaves pinnately 3-foliolate, Leaves odd pinnate, Leaf or leaflet margins entire, Leaflets opposite, Leaflets 3, Leaves glandular punctate or gland-dotted, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescences spikes or spike-like, Inflorescence axillary, Bracts conspicuously present, Bracts hairy, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals blue, lavander to purple, or violet, Banner petal ovoid or obovate, Banner petal auriculate, Wing petals narrow, oblanceolate to oblong, Wing petals auriculate, Wing tips obtuse or rounded, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens diadelphous, 9 united, 1 free, Filaments glabrous, Style terete, Style hairy, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit oblong or ellipsoidal, Fruit enclosed in calyx, Fruit beaked, Fruit hairy, Fruit 1-seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.

Psoralea rydbergii là một loài thực vật có hoa trong họ Đậu. Loài này được Cory miêu tả khoa học đầu tiên.