Medicago sativa
Medicago polymorpha
alfalfa, lucerne, purple medick
bur medic, bur-clover, bur-clover or medic, burr medic, California burclover, smooth medic, tooth bur clover, tooth medic, tooth medick
prostrate to erect.
procumbent, decumbent, or ascending.
blades obovate to linear or oblanceolate, 5–35 × 2–15 mm, margins serrate distally.
blades obovate, obcordate, or cuneate, 8–20 × 7–18(–20) mm, margins usually serrate, rarely laciniate, on distal 1/3–1/2.
3–30(–50)-flowered, racemes.
(1 or)2–6(–10)-flowered, racemes.
5–15 mm;
calyx glabrous or pubescent, hairs eglandular or glandular, lobes equal to tube;
corolla usually purple, yellow, or variegated yellow-violet, rarely violet, green, or white, [yellow-orange, pink], 2 times length of calyx.
3.5–6 mm;
calyx sparsely pubescent, hairs eglandular, lobes equal to tube;
corolla yellow, usually less than 2 times length of calyx.
curved or with 1.5–6 coils, falcate when curved, lenticular, ovoid, or cylindrical when coiled, 7–15 × 1.5–3 mm when falcate, 4–14 × 3–9 mm when coiled, glabrescent or pubescent with eglandular and/or glandular hairs;
face veins (when coiled) oblique from ventral suture, slightly branched, fusing towards dorsal suture.
with 1.5–7 coils, discoid, short to long cylindrical, or conical-truncate, 2–12 × 4–10 mm, usually glabrous, margin usually prickly, sometimes tuberculate or prickleless, prickles, when present, often relatively thin and flexible, base 2-rooted, 1 root arising in dorsal suture, other in submarginal vein;
faces moderately soft, sometimes very hard at maturity, coil face with transverse veins anastomosing in outer part of coil before entering lateral vein near coil edge.
2–12, yellow, brownish, greenish yellow, or violet-brown, reniform, 1–2.5 × 1–1.5 mm.
2–12, light yellow to brownish, reniform, 2–4 × 1.5–2.2 mm;
radicle 1/2 seed length.
margins entire or basally toothed.
margins laciniate.
= 16, 32.
= 14, 16.
Medicago sativa
Medicago polymorpha
Subspecies 6 (3, including 1 hybrid, in the flora).
Medicago sativa is the most widely grown of the temperate forage legumes. Wherever it is cultivated, escapes are likely to be found in the vicinity, and the species has become established in most countries. This polymorphic Old World species is complicated by polyploidy, hybridization, and domestication and has been divided by some (E. Small 2011) into several species (dozens, by some Russian taxonomists) and innumerable infraspecific taxa. The natural habitats of the wild progenitors of M. sativa in Asia (mostly in the former U.S.S.R.) are rapidly being decimated, and there is considerable danger that valuable genetic diversity is being lost.
According to the literature cited below, the three subspecies in the flora region should be expected in all provinces and territories of Canada, and in all states.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Medicago polymorpha is one of the more important annual medics that have been developed for use as pasture forage for dry, hot environments. About a dozen cultivars have been bred.
Medicago polymorpha is the most likely species of the genus to be confused with other species. The fruits are easily misidentified as one of the hard-fruited Medicago (M. rigidula, M. truncatula, M. turbinata), but are fairly similar to those of certain of the soft-fruited taxa, particularly M. laciniata and M. minima, two species that are also quite common as weeds. The fruit coil faces of both of the latter species have distal veinless areas. The coil face of M. polymorpha has quite reticulate venation, whereas that of M. laciniata has notably S-shaped radial veins that anastomose little. Medicago minima is a quite hairy plant, whereas M. polymorpha is almost always glabrous.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Flowers usually purple, sometimes violet, not bicolored, very rarely white; legumes with at least 1.5 coils, usually 2–6. | subsp. sativa |
1. Flowers yellow or variegated yellow-violet, rarely green or violet; legumes falcate or with fewer than 1.5 coils. | → 2 |
2. Flowers yellow; legumes falcate, less than 0.5 coil. | subsp. falcata |
2. Flowers usually variegated yellow-violet, sometimes green, yellow, or violet; legumes with 0.8–1.4 coils. | subsp. × varia |
- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
PNW Herbaria, Turner Photog. 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
- Local floras: BC, CA, OR, WA
- Local Web sites: CalFlora, CalPhotos, Flora NW,
Go Botany, 
LA Plants, 
MI Flora, 
MO Plants, PNW Herbaria - WildflowerSearch
- iNaturalist (observations)
- USDA Plants Database
- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
