Oxytropis nigrescens
Oxytropis arctica
blackish locoweed, blackish oxytrope, one-flower oxytrope
arctic locoweed, arctic oxytrope
0.5–5 cm;
stipules membranous, whitish or with light tan or grayish herbaceous tips, 5–14 mm, usually ± pilose, rarely glabrous abaxially, margins often long-ciliate, with clavate processes;
leaflets 5–15, blades elliptic to ovate, 2–10 × 1–2(–3) mm, flat, margins involute but not falcate, apex acute or obtuse, surfaces silky- or silvery-canescent, villous, strigose, or loosely pilose, rarely glabrous.
(3–)4–21 cm;
stipules membranous, fragile, strongly imbricate, grayish or yellowish, 10–20 mm, pilose abaxially becoming glabrate, margins ciliate, with clavate processes;
leaflets 3–21, alternate, opposite, subopposite, scattered, or fasciculate, blades lanceolate, elliptic, lanceolate-elliptic, or oblong, 4–40 × 2–5 mm, apex acute, surfaces pilose.
1 or 2(–5)-flowered.
2–10+-flowered.
0.3–4[–5] cm, pubescent;
bract narrowly lanceolate to linear, pilose.
4–15(–31) cm, strigulose to spreading-villous;
bract linear-lanceolate, mostly longer than pedicel, pilose.
bright pink-purple or blue-purple to white, 12–20 mm.
usually pink-purple, pinkish violet, or bluish, rarely white or yellowish, (14–)16–22 mm, wing petals 4–6 mm wide apically.
campanulate, usually black-pilose, sometimes villous, strigose, or glabrous;
tube 3–6 mm, lobes 1.8–4 mm.
cylindric, villous to shaggy-villous or pilose, hairs black and white;
tube 5–8.7 mm, lobes 1.5–6 mm.
spreading, subsessile to short-stipitate or stipitate, stipe 1.5–5 mm, oblong-ellipsoid, 18–38(–40) × 8–11 mm, unilocular or subunilocular, usually strigulose to pilose or villous, rarely glabrous.
erect, spreading, or erect-ascending, sessile or short-stipitate, ovoid-acuminate, 10–25 × 5–7 mm, bilocular or sub-bilocular, thinly papery, pilose or short-villous.
Oxytropis nigrescens
Oxytropis arctica
The Pan-Arctic Flora (http://panarcticflora.org/) splits the Oxytropis nigrescens complex into multiple species. It does not recognize O. nigrescens in the narrow sense as present in North America, restricting that species to Asia; instead, O. arctobia, O. bryophila and O. czukotica Jurtzev (not treated here) are considered present in North America. The Pan-Arctic Flora does not address the status of O. nigrescens var. lonchopoda because it grows outside the region they considered.
Varieties 3 (3 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
The relationships among subspecific taxa of Oxytropis arctica, O. campestris, and O. koyukukensis were examined by J. L. Jorgensen et al. (2003) using molecular data.
Varieties 5 (5 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Legumes long-stipitate, stipes 4–5 mm, subequal to calyx tube; Ogilvie Mountains, Yukon. | var. lonchopoda |
1. Legumes subsessile to short-stipitate, stipes 1.5–2 mm, shorter than calyx tube; Alaska, British Columbia, Northwest Territories, Nunavut, Quebec, Yukon. | → 2 |
2. Leaflets 9–15, blade surfaces silvery-canescent, villous, strigose, or glabrous; Alaska, British Columbia, Northwest Territories, Yukon. | var. nigrescens |
2. Leaflets 5–11, blade surfaces densely silky-canescent; alpine in s Yukon and n British Columbia, coastal from Mackenzie Delta eastward. | var. uniflora |
1. Plants usually 15–45 cm; racemes 10 +-flowered; leaflets 11+, alternate, opposite, or fasciculate; disjunct from Anaktuvuk, Koyukuk, Northway, Shaktoolik, Umiat, and Wiseman, Alaska, and Kluane Lake, Yukon. | var. koyukukensis |
1. Plants 4–21 cm; racemes 2–8(–10)-flowered; leaflets 3–17+, alternate, opposite, subopposite, fasciculate, or scattered; Alaska, Manitoba, Nunavut, Yukon. | → 2 |
2. Leaflets 11–17, alternate or opposite, blades broadly elliptic to oblong or lanceolate-elliptic; corollas white, fading cream; Kotzebue, Alaska, and eastward. | var. barnebyana |
2. Leaflets 3–17+, alternate, subopposite, fasciculate, or scattered, blades narrowly lanceolate to lanceolate-elliptic, or lanceolate to elliptic or oblong; corollas pink-purple to bluish, pinkish violet, or, rarely, white or yellowish; Alaska, Manitoba, Northwest Territories, Nunavut, Yukon. | → 3 |
3. Leaves 2–17(–19) cm, leaflets alternate, subopposite, or fasciculate; n Alaska east to Hudson Bay. | var. arctica |
3. Leaves 3–13(–17) cm, leaflets usually fasciculate, sometimes opposite or scattered; Hudson Bay, sw Yukon. | → 4 |
4. Calyces 3.5–4.5 mm wide when pressed, shaggy-pilose, hairs mostly dark; vicinity of Hudson Bay. | var. bellii |
4. Calyces 4–5 mm wide when pressed, shaggy-villous, hairs black and white; sw Yukon. | var. murrayi |
BC
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
