Medicago sativa L.
alfalfa (lucerne)
Fabaceae (Pea family)

Introduction to Vascular Plants


© Bryan Kelly-McArthur     (Photo ID #72686)


E-Flora BC Static Map

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

Species Information

Perennial herb from a long taproot; stems erect to decumbent, 30-100 cm tall/long, slender, finely stiff-hairy to glabrous.
Alternate, pinnately compound; leaflets 3, elliptic-oblanceolate to lance-oblong, 1-4 cm long, saw-toothed towards the rounded to squared-off, needle-pointed tip, sparsely to densely short-hairy, the terminal leaflet stalked; stipules entire, linear-lanceolate, not sheathing, 4-12 mm long.
Inflorescence a compact, head-like to cylindric, axillary raceme of (7) 20 to 80 (100) pea-like flowers, the racemes 1-4 cm long on stalks about equal to or longer than the leaves; corollas bluish-purple, occasionally pink to yellow or whitish, 7-10 mm long, the banner distinctly longer than the wings and keel; calyces a little shorter than the corollas, the awl-shaped teeth slightly longer than the tube.
Pods, linear-oblong, coiled in 2 to 3 spirals or slightly curved or sickle-shaped, strongly net-veined but not armed, hairy or glabrous, 2-15 mm long; seeds several to 20.
Two subspecies occur in BC. Fertile hybrids are reported to be fairly frequent, with flowers that range from yellow to purple, often with a metallic sheen.

1. Flowers blue, rarely pink or white; pods spirally coiled, 2-4 mm long; leaflets usually 2-4 cm long................... ssp. sativa

1. Flowers yellow, rarely violet; pods merely curved, 10-15 mm long; leaflets usually 1-2 cm long.................... ssp. falcata (L.) Arcang. (sickle medic, yellow lucerne)

SourceThe Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Brown
Present over the Summer
According to the USDA, this species is a known allelopath.
Source:  The USDA


Ecological Framework for Medicago sativa

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)
820 225 2131
Slope Gradient (%)
16 0 90

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

207 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
3 0 7
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

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

BG(63), BWBS(5), ESSF(8), ICH(3), IDF(84), MS(9), PP(32), SBPS(1)

Habitat and Range

Mesic to dry cultivated fields, roadsides and ditches (ssp. sativa), and roadsides and dry slopes (ssp. falcata) in the steppe zone; ssp. sativa - common agricultural escape in S BC west of the Coast-Cascade Mountains, infrequent in SW BC, ssp. falcata - rare, known from scattered locations in S BC; introduced from Eurasia.

SourceThe Illustrated Flora of British Columbia