Psorothamnus scoparius (A. Gray) Rydb.

Psorothamnus scoparius (A. Gray) Rydberg
Dalea scoparia A. Gray, Mem. Am. Acad. II. 4: 32. 1849. Parosela scoparia A. Heller, Cat. N. Am. PI. ed. 2. 7. 1900.
A shrub, 0.5 m. high or more, with ascending canescent and conspicuously glandularpustulate branches; leaves simple, spatulate-linear or oblanceolate, 1 cm. long or less, canescent and glandular-dotted; peduncles 2-7 cm. long; spikes subglobose or oblong, 12-15 mm. broad, dense; bracts lanceolate, 2 mm. long; calyx-tube turbinate, strongly 10-ribbed, with a row of 2-4 glands in each interval, 2.5 mm. long, white-villous; lobes triangular, 1 mm. long; corolla dark-blue; blade of the banner broadly oval, subcordate at the base and retuse at the apex, usually with a single gland near the apex, the claw 2.5 mm. long; blades of the wings oblong, with a rounded basal lobe, 5 mm. long, those of the keel-petals broadly obliquely obovate, 5 mm. long, the claws of the wings and keel-petals 2 mm. long; pod obliquely obovate, pubescent and glandular-dotted, glabrous only at the very base; body about equaling the calyx.
Type locality: Jornado del Muerto, New Mexico. Distribution: New Mexico, Chihuahua, and Coahuila.

Perennial, Shrubs, Woody throughout, Stems woody below, or from woody crown or caudex, Nodules present, Stems erect or ascending, Stems or branches arching, spreading or decumbent, Stems less than 1 m tall, Trunk or stems armed with thorns, spines or prickles, Plants gland-dotted or with gland-tipped hairs, Stems solid, Stems or young twigs sparsely to densely hairy, Leaves absent at flowering time, Leaves alternate, Leaves petiolate, Stipules inconspicuous, absent, or caducous, Stipules setiform, subulate or acicular, Stipules deciduous, Stipules free, Leaves simple, or appearing so, Leaf or leaflet margins entire, Leaflets alternate or subopposite, Leaflets 1, Leaflets 3, Leaves glandular punctate or gland-dotted, Leaves glabrous or nearly so, Inflorescences racemes, Inflorescences globose heads, capitate or subcapitate, Inflorescence axillary, Inflorescence or flowers lax, declined or pendulous, Bracts conspicuously present, Flowers zygomorphic, Calyx 5-lobed, Calyx g land-dotted or with glandular spot, Calyx hairy, Petals separate, Corolla papilionaceous, Petals blue, lavander to purple, or violet, Banner petal suborbicular, broadly rounded, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel tips obtuse or rounded, not beaked, Stamens 9-10, Stamens monadelphous, united below, Filaments glabrous, Style terete, Fruit a legume, Fruit unilocular, Fruit indehiscent, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit glabrous or glabrate, Fruit gland-dotted or with gland-tipped hairs, Fruit 1-seeded, Fruit 2-seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.

Psorothamnus scoparius is a thornless bush in the bean family (Fabaceae), native to North America. It is known as broom smokebush and broom dalea.