E-Flora BC: Electronic Atlas of the Flora of British Columbia

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

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #29482)

E-Flora BC Static Map
Distribution of Medicago polymorpha
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Species Information

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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.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

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

Habitat / Range

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

Source: The Illustrated Flora of British Columbia


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


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

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

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References