Arabis furcata
Arabis nuttallii
Cascade rock-cress, Columbia Gorge rockcress, fork-hair rock-cress
Nuttall's rockcress
simple or few from base (caudex), erect, usually unbranched, rarely branched (few) distally, (0.7–)1–3.8(–4.5) dm, (glabrous throughout or sparsely pubescent basally to distally).
simple or few to numerous from base (caudex), erect or ascending, unbranched, 0.5–2.5(–3.6) dm, (glabrous throughout or pubescent along proximal 1/2, trichomes simple).
petiole (0.4–)1–3(–4.5) cm, (glabrous or sparsely ciliate);
blades oblanceolate, spatulate, or obovate, (0.7–)1.2–3 cm × 5–17(–22) mm, margins entire or dentate, (often ciliate), apex obtuse, surfaces glabrous or sparsely pubescent, trichomes short-stalked, forked and simple.
petiole 0.3–2(–3.5) cm, (glabrous or ciliate);
blade narrowly oblanceolate, spatulate, to obovate, 0.4–2(–3) cm × 3–10(–15) mm, margins entire, (ciliate or not), apex obtuse, surfaces glabrous or sparsely to densely pubescent, trichomes simple, rarely mixed with forked ones.
(2 or) 3–5 (or 6);
blade linear, oblong, obovate, or oblanceolate, 0.7–3(–4) cm × 3–8 mm, base cuneate, not auriculate, margins usually entire, rarely few-toothed, apex obtuse, surfaces usually glabrous, rarely margins ciliate.
(1 or) 2–5(–7);
blade linear, oblanceolate, oblong, or obovate, 0.5–2.2(–3) cm × 2–8(–12) mm, base not auriculate, margins entire, (sometimes ciliate), apex obtuse, surfaces glabrous or, rarely, sparsely pubescent.
simple, (dense or lax).
simple, (dense or lax).
sepals (greenish), oblong, 3–4 × 1.5–2 mm, (usually glabrous, rarely with few trichomes subapically), lateral pair saccate basally;
petals white, spatulate, 7–11 × 2.5–4 mm, apex rounded;
filaments 3.5–5 mm;
anthers oblong, 0.8–1 mm.
sepals (greenish) oblong, 2.5–3.5 × 1.2–1.5 mm, lateral pair saccate basally, (glabrous);
petals white, oblanceolate to spatulate, (5–)6–8 × 2–4 mm, apex rounded;
filaments 2.5–4 mm;
anthers oblong, 0.6–1 mm.
suberect, ascending, or divaricate, (2–)4–17(–22) mm, (glabrous).
ascending to divaricate, (2–)5–20(–30) mm, (glabrous).
ascending to suberect, (not appressed to rachis), slightly torulose, sometimes slightly curved, strongly flattened, (2–)2.5–4(–4.6) cm × 1.7–2.2 mm;
valves each with prominent midvein extending full length;
ovules 14–26 per ovary;
style 0.5–1.2(–1.6) mm, (slender).
ascending to suberect, (not appressed to rachis), slightly torulose, sometimes slightly curved, (0.7–)1–2.5(–2.8) cm × 0.8–1.2(–1.5) mm;
valves each with distinct midvein extending full length;
ovules 10–24 per ovary;
style 0.5–1.2(–2) mm, (slender).
winged distally, oblong to broadly ovate, (1.5–)1.8–2.5(–3) × 1–1.3 mm;
wing (0.2–)0.4–0.8(–1) mm wide.
not winged, broadly ovate, 0.6–1.2(–1.5) × 0.5–1 mm.
= 32.
Arabis furcata
Arabis nuttallii
Arabis furcata is known in Washington from Chelan, Kittitas, Klickitat, Okanogan, Skamania, and Yakima counties, and in Oregon from Clackamas, Hood River, Multnomah, and Wasco counties.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Arabis nuttallii, the second most widespread native North American species of the genus, is variable in density of indumentum, types of trichomes, plant height, pedicel length, fruit width, leaf shape, flowering and fruiting time, and elevation. As indicated by R. C. Rollins (1941, 1993), the variation seems to be sporadic and does not correlate with clear-cut entities and, therefore, the species cannot be subdivided meaningfully.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
BC
