Arabis crucisetosa

Constance & Rollins

Proc. Biol. Soc. Wash. 49: 147. 1936

Treatment appears in FNA Volume 7. Treatment on page 262. Mentioned on page 258.
Perennials; (caudex usually simple, rarely branched, covered with persistent petiolar remains); sparsely to densely pubescent basally, trichomes short-stalked, cruciform or 3-rayed, stellate, (to 0.4 mm in diam.). Stems simple or few from caudex, erect, unbranched or rarely branched (few) distally, (1–)1.5–4(–5) dm, (glabrous throughout or sparsely pubescent proximally). Basal leaves: petiole 0.5–2.5(–3) cm; blade oblanceolate to obovate, (0.6–)1–3.5(–4.5) cm × (3–)5–15(–20) mm, margins entire or dentate, (not ciliate), apex obtuse, surfaces uniformly pubescent, trichomes short-stalked, stellate. Cauline leaves 3 or 4(–6); blade linear, oblong or oblanceolate, 1–3(–4) cm × (1.5–)3–7(–10) mm, base cuneate, not auriculate, margins usually entire, rarely few-toothed, apex obtuse, surfaces glabrous or sparsely pubescent at least along margin. Racemes simple. Fruiting pedicels ascending to divaricate, (5–)8–20 mm, (glabrous). Flowers: sepals (greenish), oblong, 2.5–4 × 1–1.5 mm, lateral pair saccate basally; petals white, oblanceolate, 7–9 × 2.5–3.5 mm, apex rounded; filaments 2.5–4 mm; anthers oblong, 0.8–1 mm; (gynophore to 0.5 mm). Fruits divaricate, slightly torulose, sometimes slightly curved, slightly flattened, (1.3–)1.7–3.5(–4) cm × 1–1.5 mm; valves each with obscure midvein extending to middle; ovules 14–28 per ovary; style 0.5–1.3 mm. Seeds not winged, oblong, 1–1.2 × 0.5–0.6 mm. 2n = 32.

Phenology: Flowering Apr–Jun.
Habitat: Open woods, rocky bluffs, steep banks, canyon margins
Elevation: 400-1800 m

Discussion

Arabis crucisetosa is known from Idaho, Lewis, and Nez Perce counties in Idaho, from Wallowa County in Oregon, and from Asotin County in Washington.

References

None.

Lower Taxa

No lower taxa listed.