Lotus corniculatus
Sp. Pl. 2: 775. 1753. (as corniculata)
Herbs annual or perennial, 5–70 cm, glabrous or sparsely pilose to strigose; usually taprooted, rarely rhizomatous. Stems ascending or prostrate, solid, not succulent. Leaves 5–30 mm; rachis (1–)2–10 mm; leaflet blades sometimes asymmetric, obovate to oblanceolate, oblong, or ovate, 4–22 × 2–11 mm, length 1.6–3(–4) times width, apex obtuse and mucronate or acuminate. Peduncles decumbent to erect, 1.5–12 cm. Inflorescences (1–)3–8(–10)-flowered; bracts (1–)3-foliolate. Flowers 10–17 mm; calyx 5–7.5 mm, lobes not recurved in bud, usually triangular, rarely ovate, (1.5–)2.5–4.5 mm, shorter to slightly longer than tube, tube villous; petals bright yellow, marked with red, turning orange, 8–14 mm, wings shorter to longer than keel. Legumes brown, narrowly oblong, 15–35 × 2–3 mm, not septate. Seeds 5–30, yellowish or light to dark brown, mottled or sometimes not, globose to round-oblong, 1–1.7 mm, smooth. 2n = 24.
Phenology: Flowering summer.
Habitat: Open, often wet disturbed, ruderal sites, lawns, fields, roadsides.
Elevation: 0–1800 m.
Distribution
St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Sask., Yukon, Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Eurasia, n Africa, introduced also in Mexico, Central America, South America, Atlantic Islands (Iceland), Australia.
Discussion
Lotus corniculatus has been widely introduced both as a forage crop and for roadside stabilization throughout North America. M. D. Ross and W. T. Jones (1985) presented evidence that L. corniculatus is an allotetraploid derived from the hybrid between either L. tenuis or L. alpinus (Seringe) Schleicher ex Ramond, as the pistillate parent, and L. uliginosus. This would explain the close morphological similarity with L. tenuis.
Selected References
None.