Annual herb; stems prostrate to erect, 10-50 cm long/tall, glabrous or sparsely short-hairy.
Alternate, pinnately compound; leaflets 3, egg- to heart-shaped with wedge-shaped bases, 1-2.5 cm long, not blotched, short-hairy to glabrous, fine-toothed toward the tip; stipules narrowly egg-shaped, deeply cut into long teeth, 3-7 mm long.
Inflorescence of 2 to 5 pea-like flowers in a reduced, axillary raceme on a stalk shorter than the leaves, the racemes 4-8 mm long; corollas yellow, 3-5 mm long, the banner longer than the wings and keel; calyces bell-shaped, 3 mm long, the awl-shaped teeth slightly longer than the tube.
Pods, coiled in 2 to 5 spirals, forming a drum-shaped body about 5 mm in diameter, the margins with straight or hooked spines as much as 3 mm long, or occasionally spineless; seeds several.
If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.
Illustration Source: The Illustrated Flora of British Columbia
Present from Spring to Summer
Source: The USDA
||Value / Class
Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
of field plots
species was recorded in:
BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in
Source: Klinkenberg 2013
Synonyms and Alternate Names:
Medicago apiculata auct. non Willd. [misapplied]
Medicago denticulata Willd.
Medicago hispida var. apiculata (Willd.) Urban
Medicago hispida var. confinis (W.D.J. Koch) Burnat
Medicago polycarpa Willd.
Medicago polymorpha (Willd.) Shinners
Medicago polymorpha var. brevispina (Benth.) Heyn
Medicago polymorpha var. ciliaris (Ser.) Shinners
Medicago polymorpha var. nigra
Medicago polymorpha var. polygyra (Urban) Shinners
Medicago polymorpha var. tricycla (Gren. & Godr.) Shinners
Medicago polymorpha var. vulgaris (Benth.) Shinners