Acmispon denticulatus
Acmispon plebeius
meadow birds-foot trefoil, meadow lotus, Mohave trefoil, riverbar bird's-foot-trefoil, riverbar lotus, riverbar trefoil, tooth lotus
1(–5), decumbent to erect, apically or basally coarse-branched, herbaceous, leafy.
1–10+, decumbent to ascending, branched, herbaceous, sometimes slender, leafy, base with or without persistent leaves.
subpinnate, pinnate, or palmate;
stipules glandlike or absent; petiolate;
rachis 5–12 mm, flattened;
leaflets 2–4, often 1 or 2 on one side and 2 terminal, blades elliptic to obovate (lateral sometimes asymmetric), margins denticulate or entire, apex acute to obtuse, surfaces hirsute.
irregularly pinnate to subpalmate with a terminal trefoil, often dimorphic (proximal with smaller, rounder leaflets);
stipules glandlike;
subsessile to short-petiolate;
rachis (1.5–)5–10 mm, flattened;
leaflets (3 or)4 or 5(–7)[–13], blades obovate (widely obovate) to linear-oblanceolate [elliptic], apex emarginate or obtuse to acute, surfaces strigose to villous.
1 or 2-flowered.
1–3(or 4)-flowered.
± sessile;
bract absent.
ascending, 10–70(–90) mm, longer than leaves;
bract absent or 1–3[–5]-foliolate, subtending umbel.
5–8 mm;
calyx 3–5 mm, tube hirsute or glabrous, lobes subulate, ± denticulate;
corolla cream-white to pale yellow, banner purple-tinged, keel tip yellowish, claws shorter to slightly longer than calyx tube, banner ascending, wings ± equaling keel, with deep, triangular auricle;
style curved, glabrous.
10–16(–20) mm;
calyx 5–8.5[–10] mm, tube villous, lobes lanceolate to subulate;
corolla yellow, turning orange or red [banner red, keel and wings white], claws ± equaling calyx tube, banner ascending to 45°, wings longer than keel;
style straight, glabrous.
persistent, solitary or paired, exserted, erect or spreading, tawny, straight, compressed, slightly constricted, not septate, widely oblong, 8–20 × 3 mm, leathery, apex abruptly downward angled and curved, dehiscent, smooth, margins often undulate-verrucose, strigose or glabrous.
persistent, exserted, erect to spreading, green or purplish brown [ashy], straight or ± curved, compressed, slightly constricted, imperfectly septate, linear-oblong, 17–35 × 2–3 mm, leathery, apex short-beaked, dehiscent, smooth, margins keeled, strigillose [glabrate].
(2 or)3(or 4), gray, faintly mottled, asymmetrically ± angular-obovoid, flattened, smooth.
10–18, dark brown, ± mottled, oblong, dull, ± compressed, smooth.
= 12.
= 14.
Acmispon denticulatus
Acmispon plebeius
Acmispon denticulatus occurs in California from the San Francisco Bay area, Sacramento Valley, and northern Sierra Nevada Foothills to the northwest, Cascade Range and Modoc Plateau, into adjacent southern Oregon (Siskiyou and Klamath regions), northward on both sides of the Cascade Range into southern British Columbia, with eastern outliers in southwestern Utah (Washington County), and in south-central Idaho (Lincoln County).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Acmispon plebeius occurs in the plateaus of southern Utah and into Lincoln County, Nevada, as well as in the plateaus and ranges of Arizona and New Mexico. It is reported to hybridize with A. neomexicanus and A. rigidus (A. M. Ottley 1944; D. Isely 1981), as well as A. wrightii (Isely).
Lotus nummulus Dayton is an illegitimate, superfluous name that pertains here.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)- LBJ Wildflower Center
- SEINet
- Plants of the World Online
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