Astragalus tyghensis
Proc. Biol. Soc. Wash. 49: 110. 1936.
Plants (10–)15–55 cm, densely villous-tomentose; from superficial caudex; taproot woody. Stems prostrate or decumbent to ascending, densely villous-tomentose. Leaves 5–14 cm; stipules distinct, 3–6 mm, herbaceous becoming membranous; leaflets (7–)15–21, blades oval-obovate, 6–17 mm, apex obtuse to subacute, surfaces villous-tomentose. Peduncles erect or incurved-ascending, 5–12 cm. Racemes (10–)20–40-flowered, flowers spreading; axis (1–)1.5–12 cm in fruit; bracts 2–5 mm; bracteoles 0. Pedicels 0.5–1 mm. Flowers 9–12 mm; calyx broadly campanulate, 6.6–7.8 mm, silky-villous, tube 3.9–4.5 × 3.5–4.1 mm, lobes narrowly subulate, 2.7–3.5 mm, somewhat accrescent, covering most or all of mature legume; corolla pale yellow, drying ochroleucous, pubescent abaxially; banner recurved through 50°; keel 7.1–8.2 mm, apex obtuse-deltate. Legumes spreading or somewhat declined, straight, obliquely ovoid, obscurely 3-sided compressed, 4.5–6 × 3 mm, stiffly papery, tomentulose, hairs 1+ mm; contracted basally into pseudostipe, 0.4–0.6 mm. Seeds 6–8.
Phenology: Flowering May–Jul.
Habitat: Sagebrush and open oak woodlands, on basaltic substrates.
Elevation: 400–600 m.
Discussion
Astragalus tyghensis is known from the eastern foothills of the Cascade Range in Wasco County.
Selected References
None.