Medicago sativa subsp. falcata (L.) Arcang.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Subspecies Description - Laxer than ssp. sativa, often ± prostrate; fls yellow; pods falcate (or nearly straight) or coiled to 1.5 turns. Native of Siberia and n. Europe, now widely cult. and escaped, but not so common as ssp. sativa.