Medicago polymorpha L.
bur-clover (burclover)
Fabaceae (Pea family)

Introduction to Vascular Plants


© Jamie Fenneman     (Photo ID #29482)


E-Flora BC Static Map

Distribution of Medicago polymorpha
Click here to view the full interactive map and legend

Species Information

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.

SourceThe Illustrated Flora of British Columbia


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.

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
Source:  The USDA


Ecological Framework for Medicago polymorpha

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
Slope Gradient (%)
15 15 15

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

201 202 202
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

Habitat and Range

Mesic to dry fields and waste places, often with sandy or gravelly soil; rare in SW BC; introduced from Eurasia.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Medicago apiculata auct. non Willd. [misapplied]
Medicago denticulata Willd.
Medicago hispida
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