Herbs 6–18 dm, glabrate (except racemes densely villous). Stems thick, erect, solitary or clustered, few-branched, from woody root­stock; branches spreading at 45–60º, moderately zigzag. Leaves: stipules persistent, elliptic to ovate, 1.5–4.5 × 0.9–2.4 cm, base oblique to cuneate, apex acute to obtuse; petiole 2–5(–6) cm; leaf­let blades elliptic, 4–9.5 × 1.8–4.4 cm, lateral veins 6–8 pairs, conspicuously net-veined abaxially, apex acute to obtuse, surfaces sparsely villous abaxially, glabrate adaxially. Peduncles 6–13 cm; bracts deciduous, widely ovate to widely obovate, 5–7 × 5–6(–8) mm. Racemes 10–50-flowered, 15–50 cm; flowers in whorls of 2 or 3 or scattered. Pedicels 2–3 mm, densely villous. Flowers 1.7–1.9 cm; calyx 7–8 × 5–6.5 mm at limb, lobes 2–3 mm, much shorter than tube; wing and keel petals asymmetrically oblong-rhombic; ovary velutinous; ovules 12–16. Legumes ascending, straight to slightly arcuate, 4–5.5 × 0.4–0.6 cm, densely tomentose to villous. Seeds 7–12, olive brown, elliptic, 3–3.5 × 1.8–2 mm, beaked. 2n = 18.

Phenology: Flowering May–Jun(–Jul).
Habitat: Open areas of deciduous oak woodlands.
Elevation: 1000–1600 m.

Distribution

• Generated Map
• Legacy Map

Ala., Conn., Ga., Maine, Md., Mass., N.H., N.J., N.Y., N.C., Pa., S.C., Tenn., Vt., Va.

Discussion

Thermopsis villosa is a distinctive, stiffly erect species of the southern Appalachian ridges and upper valleys. Locally naturalized populations occur where the species has been cultivated farther north.

Selected References

None.

Lower Taxa

None.