Whiterim Scurfpea

Pediomelum subacaule (T. & G.) Rydberg
Psoralea subacaulis T. & G. Fl. N. Am. 1: 302. 1838. Lotodes subacaule Kuntze, Rev. Gen. 194. 1891.
A subacaulescent perennial, with a fusiform tuberous root 5-10 cm. long, 1-3 cm. thick; stem above ground very short; leaves digitately 5-7-foliolate, clustered at the base; stipules ovate, scarious, 1-2 cm. long; petioles 4—8 cm. long, hirsute-villous; leaflets 1.5-4 cm. long, 6-10 mm. wide, oblanceolate or oblong-oblanceolate, obtuse or acute, glabrous except the ciliate margins and mid veins beneath; peduncles 4— 1 cm. long, villous-hirsute; spikes dense, 2-6 cm. long; bracts ovate-lanceolate, 1-1.5 cm. long, ciliate; calyx hirsute; tube 3 mm. long; upper four lobes triangular, very short, acute, the lowest one obovate or spatulate, rounded or obtuse at the apex, 3 mm. long; corolla purple, 12-15 mm. long, similar to that of P. cuspidatum; pod hirsute, ovoid, the flat beak shorter than the body.
Type locality: Nashville, Tennessee. Distribution: Tennessee.

Perennial, Herbs, Stems woody below, or from woody crown or caudex, Taproot present, Tubers or tuberous roots present, Nodules present, Stems very short, acaulescent or subacaulescent, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Stems hairs pilose or spreading, Leaves alternate, Leaves clustered on spurs or fasicles, Leaves petiolate, Stipules conspicuous, Stipules green, triangulate to lanceolate or foliaceous, Stipules persistent, Stipules free, Stipules toothed or laciniate, Leaves compound, Leaves palmately 5-11 foliate, Leaf or leaflet margins entire, Leaflets 5-9, Leaves glandular punctate or gland-dotted, Leaves glabrous or nearly so, Leaves hairy on one or both surfaces, Inflorescences spikes or spike-like, Inflorescence axillary, Bracts conspicu ously present, Flowers zygomorphic, Calyx 5-lobed, Calyx hairy, Petals separate, Corolla papilionaceous, Petals clawed, Petals white, 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.

Pediomelum subacaule is a species of flowering plant in the legume family known by the common names Nashville breadroot and whiterim scurfpea. It is native to a small area of Eastern North America, only being found in limestone cedar glades of the Interior Low Plateau and Ridge and Valley ecoregions of Alabama, Georgia, and Tennessee.

This species is a geophyte, and is well adapted to the desert-like conditions of flat limestone glades. The plants flower in April and set seed in May, then quickly die back in summer, beginning new growth when the cool temperatures of fall set in. This life cycle is in harmony with the availability of water in the harsh cedar glade environment, which is often saturated with water in the winter and spring but extremely hot and dry during the summer.

Pediomelum subacaule là một loài thực vật có hoa trong họ Đậu. Loài này được (Torr. & A.Gray) Rydb. miêu tả khoa học đầu tiên.