Heil et al. 2013, Correll and Johnston 1970, Allred and Ivey 2012, Martin and Hutchins 1980

Duration: Perennial Nativity: Native Lifeform: Forb/Herb General: Perennial herb, 10-30 cm tall, from a slightly woody base and slender, creeping rhizomes; stems erect or ascending, branching near the base, silvery-pubescent. Leaves: Alternate and pinnately compound, 3-6 cm long, with 13-23 leaflets per leaf; leaflets oblong to obovate, 5-10 mm long and and one-third as wide, usually folded along the midvein, hairy on the underside and mostly glabrous on the upper surface. Flowers: White to cream, held above the leaves in erect racemes, 3-9 cm long; flowers 15-20 mm long, with pea-flower morphology (papilionaceous); sepals 8-10 mm long, fused into a tube and topped with 5 triangular teeth; petals snowy white and fading to a cream color. Fruits: Pods 1-4 cm long, ovate-oblong and stongly constricted between the seeds, hairy, and tipped with a long-pointed beak; containing 1-3 seeds. Ecology: Found in disturbed areas, riparian zones, grasslands, and along roadsides, in loamy and sandy soil or rocky ground, from 4,000-6,500 ft (1219-1981 m); flowers April-June. Distribution: WY and SD south to AZ, NM and TX; south to c MEX. Notes: This species could be easily mistaken for an Astragalus. The technical difference between Astragalus and Sophora is in the stamens. Sophora has 10 stamens that are all distinct from each other, while Astragalus has 10 stamens but 9 of them are fused together along the length of the filaments. The fused filaments form a sheath which wraps around the pistil and style. Ways to recognize this species without looking inside the flower are its low, leafy stature; leaves and stems covered with silvery hairs; whitish pea-flowers in an erect raceme which emerges above the leaves; and seed pods that are constricted between the seeds and have a long narrow pointed beak at the top. The species is rhizomatous, so it will tend to grow in colonies. Ethnobotany: May or may not be toxic. Used by Navajos as sheep forage. Etymology: Sophora is from sophera, the Arabic word for a leguminous tree; nuttaliana honors Thomas Nuttall (1786-1859), an English botanist and zoologist who collected in North America. Editor: FSCoburn 2015, AHazelton 2017