Arabis crucisetosa
Arabis modesta
cross-hair rock-cress, wetsoil rock-cress
modest rock-cress, Rogue Canyon rock-cress
simple or few from caudex, erect, unbranched or rarely branched (few) distally, (1–)1.5–4(–5) dm, (glabrous throughout or sparsely pubescent proximally).
simple or few from base (caudex), erect, usually unbranched, rarely branched (few) distally, 2.2–5.5(–6.7) dm, (usually pubescent throughout, rarely subglabrate distally, trichomes stellate).
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.
petiole 1–4(–5) cm, (rarely minutely ciliate near base);
blade oblanceolate to obovate, (0.8–)2–4.5(–6) cm × (4–)10–20(–25) mm, margins entire, repand, or dentate, (not ciliate), apex obtuse, surfaces pubescent, trichomes short-stalked, stellate.
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.
(2–)4–6(–9);
blade oblong or ovate, 1–3.5(–4.5) cm × (3–)6–10(–20) mm, base not auriculate, margins entire, repand, or dentate, apex obtuse or acute, surfaces pubescent, trichomes short-stalked, stellate.
simple.
simple, (dense).
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).
sepals (purple), oblong, (4–)5–6.5(–8) × 1.5–2 mm, lateral pair saccate basally;
petals purple, spatulate, (10–)12–16(–20) × 4–6(–7) mm, apex rounded;
filaments (4–)5–8 mm;
anthers narrowly oblong, 1.3–2 mm.
ascending to divaricate, (5–)8–20 mm, (glabrous).
ascending to divaricate, 7–18(–25) mm.
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.
suberect to divaricate, sometimes slightly curved, slightly torulose, (2.8–)3.5–6 cm × 1.5–2 mm;
valves each with prominent midvein extending to middle or full length;
ovules 20–34 per ovary;
style 0.5–1(–1.5) mm.
not winged, oblong, 1–1.2 × 0.5–0.6 mm.
winged distally, oblong, 1.7–2.2 × 0.9–1.2 mm;
wing 0.2–0.5 mm wide.
= 32.
= 32.
Arabis crucisetosa
Arabis modesta
Arabis crucisetosa is known from Idaho, Lewis, and Nez Perce counties in Idaho, from Wallowa County in Oregon, and from Asotin County in Washington.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Arabis modesta, known only from Napa, Siskiyou, and Yolo counties (California), and Jackson and Josephine counties (Oregon), and the following four species form a well-defined group easily separated from the first nine species above by their large, purple petals. Arabis modesta is readily distinguished from other purple-flowered Arabis by having very fine, short-stalked cruciform and 3-rayed, instead of simple and 2-rayed, forked trichomes. Arabis blepharophylla has broadly winged, orbicular seeds, and the other purple-flowered species (A. aculeolata, A. mcdonaldiana, A. oregana) have oblong seeds that are not winged or narrowly winged distally. The lines separating these three species are not as well-defined as those of A. blepharophylla and A. modesta, and further studies are needed to resolve them. I prefer to maintain all five species of purple-flowered Arabis as distinct until thorough molecular and hybridization studies are conducted. In the absence of such studies, it is unwise to make any nomenclatural changes.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
OR
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CA
