Streptanthus howellii

Perennials; (caudex simple or branched); (glaucous), glabrous. Stems usually unbranched, rarely branched distally, 3-8 dm. Basal leaves (soon withered); not rosulate; petiolate; blade (somewhat fleshy), similar to cauline. Cauline leaves (petiolate); blade broadly spatulate-obovate to suborbicular, or (distally) narrowly oblong-oblanceolate to linear, 1.5-10 cm × 5-45 mm, base (distally) cuneate to attenuate, not auriculate, margins entire, repand, or obtusely dentate, (entire distally). Racemes ebracteate, (lax). Fruiting pedicels divaricate to ascending, (straight), 7-17 mm. Flowers: calyx subcampanulate; sepals purplish, oblong, 5-8 mm, not keeled; petals maroon to purple, 8-12 mm, blade 3-5 × 0.5-1 mm, margins not crisped, claw 5-7 mm, wider than blade; stamens in 3 unequal pairs; filaments (distinct): abaxial pair 5-6 mm, lateral pair 4-5 mm, adaxial pair 6-7 mm; anthers (all) fertile, 3-3.5 mm; gynophore 0.5-5 mm. Fruits divaricate-ascending, smooth, straight to slightly curved inwards, flattened, 5.5-12 cm × 2.5-3.2(-3.5) mm; valves each with prominent midvein; replum straight; ovules 24-44 per ovary; style 0.3-3 mm; stigma subentire. Seeds broadly oblong to suborbicular, 3-4 × 2-3 mm; wing 0.5-1.1 mm wide, continuous. 2n = 28.

Flowering Jun-Jul. Dry serpentine slopes and ridges in open conifer-hardwood forests; of conservation concern; 600-800 m; Calif., Oreg.

Streptanthus howellii is known from the Klamath Mountains in California (Del Norte and Siskiyou counties) and Oregon (Curry and Josephine counties).