Herbs: shoots glabrescent to pubescent, hairs eglandular [glan­dular]. Stems prostrate to erect. Stipules: margins entire or basally toothed. Leaflets: blades obovate to linear or oblanceolate, 5–35 × 2–15 mm, margins serrate distally. Inflo­rescences 3–30(–50)-flowered, racemes. Flowers 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. Legumes 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. Seeds 2–12, yellow, brownish, greenish yellow, or violet-brown, reniform, 1–2.5 × 1–1.5 mm. 2n = 16, 32.

Distribution

Introduced; n Mexico, Eurasia, introduced also in West Indies, Central America, South America (Argentina, Brazil, Chile, Uruguay), Pacific Islands, Australia.

Discussion

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.

Selected References

None.

Lower Taxa

Medicago sativa subsp. falcata, Medicago sativa subsp. sativa, ×varia

Key

1	Flowers usually purple, sometimes violet, not bicolored, very rarely white; legumes with at least 1.5 coils, usually 2–6.	Medicago sativa 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.	Medicago sativa subsp. falcata
2	Flowers usually variegated yellow-violet, sometimes green, yellow, or violet; legumes with 0.8–1.4 coils.	Medicago sativa subsp. × varia