West silver bladderpod

Perennials; (diminutive); caudex simple or branched, (buried, with thatch of persistent leaf bases distally); (appearing silvery gray-green to silvery purple), densely pubescent, trichomes usually 5 or 6 (rarely 7)-rayed, rays bifurcate or incompletely so, (relatively short, stout, umbonate, moderately tuberculate to nearly smooth, lower layer smoother). Stems 1-5 from base, prostrate to slightly decumbent, (arising laterally, also erect or ascending from tuft of basal leaves, unbranched, purple-green), 0.08-0.3 dm. Basal leaves: (petiole slightly winged); blade oblanceolate, elliptic, or rhombic, (mostly flat, sometimes somewhat folded), 0.6-2.7 cm, (base tapering to petiole), margins entire, (apex rounded to rounded-acute). Cauline leaves: (3-7, shortly petiolate or sessile); blade elliptic to oblanceolate, 0.3-0.5 cm, margins entire. Racemes crowded, (ca. 3-7 fruits). Fruiting pedicels (ascending, straight), 1.8-3.4 mm. Flowers: sepals (greenish yellow), linear-triangular, 3.7-5 mm, (lateral pair subsaccate); petals oblanceolate to narrowly obovate, 4.5-9 mm. Fruits (shortly stipitate, purple or greenish purple in age), slightly didymous, ovoid to obpyriform, 3-5 mm (wider than long, base rounded-obtuse, apex rounded, flattened, or slightly emarginate); valves (inflated, slightly wider than replum), pubescent, trichomes scattered; replum obovate to orbicular-obdeltate, apex rounded, obtuse, or truncate; septum complete or medially small-perforate; ovules 4-6(-8) per ovary; style 2-3.6 mm. Seeds relatively plump, (ovate to suborbicular, usually rounded on one side, ± flat or concave on the other, not mucilaginous when wetted).

Flowering Jun-early Jul. Tundra areas with islands of Engelmann spruce on Leadville limestone, amidst limestone cobbles and gravel; 3500-3700 m; Colo.

Physaria scrotiformis is known only from La Plata County.