Arabis patens
Arabis olympica
spreading rockcress
Olympics rockcress
simple or several from base (rosette), erect, often branched distally, (1.8–)2.5–4.5(–5.5) dm, (hirsute at least basally).
simple or few from base (caudex), erect, unbranched, 0.7–1.1 dm, (pubescent throughout, trichomes short-stalked, forked).
petiole (0.7–)2–5 cm;
blade usually ovate to oblanceolate, rarely cordate, (0.8–)1.5–3 cm × 5–17 mm, margins dentate or serrate, surfaces sparsely to densely pubescent, trichomes simple or forked.
petiole 0.3–0.6 cm, (sparsely ciliate);
blades oblanceolate to obovate, 0.4–1cm × 2–7 mm, margins entire or repand, (ciliate), apex obtuse, surfaces sparsely pubescent, trichomes simple and forked.
(5–)8–20(–27), (overlapping or not);
blade ovate to oblong or lanceolate, (2–)3–7.5(–9) cm × (10–)13–25(–35) mm, base amplexicaul, margins usually dentate or serrate, sometimes entire, surfaces hirsute.
4–6;
blade oblong, 0.6–0.8 cm × 2–3 mm, base not auriculate, margins entire, (ciliate), apex obtuse.
branched.
simple, (dense).
sepals oblong, 2.5–4.5 × 1–1.5 mm, lateral pair slightly saccate basally;
petals white, spatulate, (5–)6–9 × 2–3.5 mm, apex obtuse;
filaments 3–5 mm;
anthers oblong, 0.8–1.2 mm.
sepals (greenish), ovate, 1.5 × 0.5 mm, lateral pair not saccate basally, (glabrous);
petals white, oblanceolate, 3.5–4 × 1 mm, apex rounded.
ascending to divaricate-ascending, (7–)10–20(–24) mm, (glabrous or sparsely pubescent).
erect, (subappressed to rachis), 5–6.5 mm, (glabrous).
divaricate to erect-ascending, (not appressed to rachis), torulose, 2.2–4.6 cm × 0.8–1.2mm;
valves each with prominent midvein extending to middle or full length;
ovules 16–28 per ovary;
style 0.5–2 mm, (slender).
erect, (appressed to rachis), slightly torulose, 2–2.3 cm × 1 mm;
valves each with distinct midvein extending full length;
ovules 28–34 per ovary;
style 0.2–0.3 mm, (stout).
narrowly winged distally, oblong, 1–1.6 × 0.6–0.8 mm;
wing 0.05–0.1 mm.
winged distally, oblong, ca. 1 × 0.5 mm;
wing ca. 0.1 mm wide.
Arabis patens
Arabis olympica
Arabis olympica, which is known from two collections, J. B. Flett s.n. (holotype, US; isotype, WS) and N. Buckingham 1577 (WS) that were made from Jefferson and Clallam counties, respectively, was reduced by R. C. Rollins (1936, 1941, 1993) to a variety of A. furcata. An examination of the type collections of both species reveals that they are distinct. Although the fruits and seeds of A. olympica are not fully mature, they are clearly different in width and orientation from those of A. furcata at the same developmental stage. The striking differences in fruit width and orientation, stem indument, and seed and flower size support their maintenance as distinct species. Although both species grow in Washington, the range of A. olympica seems to be restricted to Clallam and Jefferson counties and is disjunct from Chelan, Kittitas, and Yakima counties, where A. furcata grows.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
MD Biodiversity
WildflowerSearch
iNaturalist
USDA Plants Database
WA
Flora NW
PNW Herbaria
