Monographs Details:
Authority:
Isely, Duane. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. New York Bot. Gard. 25 (3): 1-264.
Isely, Duane. 1981. Leguminosae of the United States. III. Subfamily Papilionoideae: tribes Sophoreae, Podalyrieae, Loteae. Mem. New York Bot. Gard. 25 (3): 1-264.
Family:
Fabaceae
Fabaceae
Description:
Species Description - Ascending or procumbent, usually glabrate (in U.S.) perennial with clustered, solid or hollow stems .5-4 dm of superficial origin from a tap root. Leaves edento-lotus type; leafstalk 2-7 mm; terminal leaflets of midstem blades obovate, asym-metric-oblanceolate to oblong, 5-15 cm, 1.5-2.5(-5) r. Umbels ascending or erect, long-pedunculate, subtended by a usually trifoliolate bract, with (2-)4-8 ascending and spreading flowers 10-14 mm (8-18 mm among experimental garden introductions); floral bracts sometimes discernible as dark, glandular scales. Pedicels 1-2 mm. Hypanthium-calyx broadly obconic, 2.8-3.5 mm; teeth subulate, 1.8-2.5 mm, not spreading in bud, ± tube above hypanthium. Corolla bright yellow, becoming orange and marked with red; keel broadly subauriculate at base, upturned in middle at 90° and lunate-porrect. Ovules 20-40. Legumes cor-niculate, narrowly oblong, terete, 1.5-3.5 cm x ca. 2 mm, slender-beaked, dehiscent. Seeds few-many. Lotus.
Species Description - Ascending or procumbent, usually glabrate (in U.S.) perennial with clustered, solid or hollow stems .5-4 dm of superficial origin from a tap root. Leaves edento-lotus type; leafstalk 2-7 mm; terminal leaflets of midstem blades obovate, asym-metric-oblanceolate to oblong, 5-15 cm, 1.5-2.5(-5) r. Umbels ascending or erect, long-pedunculate, subtended by a usually trifoliolate bract, with (2-)4-8 ascending and spreading flowers 10-14 mm (8-18 mm among experimental garden introductions); floral bracts sometimes discernible as dark, glandular scales. Pedicels 1-2 mm. Hypanthium-calyx broadly obconic, 2.8-3.5 mm; teeth subulate, 1.8-2.5 mm, not spreading in bud, ± tube above hypanthium. Corolla bright yellow, becoming orange and marked with red; keel broadly subauriculate at base, upturned in middle at 90° and lunate-porrect. Ovules 20-40. Legumes cor-niculate, narrowly oblong, terete, 1.5-3.5 cm x ca. 2 mm, slender-beaked, dehiscent. Seeds few-many. Lotus.
Discussion:
L. macbridei Neis. (1912). L. caucasicus Kupr. (1945). 2n = 24 (Grant, 1965; with citations of numerous determinations). We have three established species of the ”Lotus corniculatus group” (Ball and Chrtkova-Zertova, 1968), of which L. corniculatus is by far the most widely distributed and common. It is easily distinguished from the rhizomatous L. ulig-inosus, and unsatisfactorily so from L. tenuis, which usually has narrower leaflets and commonly smaller flowers (see key). Although Isely (1951) segregated L. tenuis, most North American taxonomists have treated it as a synonym or variety of L. corniculatus because the two cannot always be discriminated, and Heyn (1970a), in the Flora of Turkey, took the same position. Although U.S. populations of L. corniculatus differ in habit and leaflet proportions, they are much less diverse than those in Europe, and present no taxonomic problems save the differentiation of L. tenuis as noted above. The classification of related experimental introductions is uncertain. Ball and Chrtkova-Zertova (1968) listed 12 binomials among the “L. corniculatus group,” stating that they were uncertain which should be considered species. Grant and students, in several publications (e.g., Grant, 1965), regarded most segregates as species. In the most recent revision of L. corniculatus (Chrtkova-Zertova, 1973; “central and northern Europe”), L. corniculatus was defined as a polymorphic, tetraploid species including 14 varieties within the geographic area studied. Lotus corniculatus as provisionally defined herein is equivalent to the tetraploid elements of Ball and Chrtkova-Zertova’s (1968) complex. Possibly these tetra-ploids include several species. For example, Harney and Grant (1964a), on the data, treat L. caucasicus at the specific level and it is so listed in U.S.D.A. PI introductions. My listing of L. caucasicus as a synonym must be regarded as nolle prosequi. Birdsfoot trefoil, one of the most important forage legumes in the world is grown in the United States on more than 2 million acres, primarily in the northeastern and north-central states, and the cismontane Pacific. Of high nutritive value, it is more tolerant of acid, infertile and poorly drained soils than other forage legumes, and has replaced much red and white clover, and timothy in the east. It is a common component of permanent pastures in the central states. It does not cause bloat, a common danger from alfalfa and the clovers. Usually produced in mixtures with grasses, it may be grazed, or cut for hay or silage. Its limitations are of stand establishment and susceptibility to diseases in hot, humid climates. Agronomic kinds include several recently developed cultivars. Since the entry of birdsfoot trefoil into American agriculture is relatively recent, the still useful classic study is that of MacDonald (1946). Recent literature is cited by Seaney (1974) in Heath et al. (1974), and by authors of other books or papers on forages. The Lotus Newsletter (editor, W. F. Grant, Genetics Laboratory, MacDonald Campus of McGill University, Quebec, Canada) provides continuing reference to current publications.
L. macbridei Neis. (1912). L. caucasicus Kupr. (1945). 2n = 24 (Grant, 1965; with citations of numerous determinations). We have three established species of the ”Lotus corniculatus group” (Ball and Chrtkova-Zertova, 1968), of which L. corniculatus is by far the most widely distributed and common. It is easily distinguished from the rhizomatous L. ulig-inosus, and unsatisfactorily so from L. tenuis, which usually has narrower leaflets and commonly smaller flowers (see key). Although Isely (1951) segregated L. tenuis, most North American taxonomists have treated it as a synonym or variety of L. corniculatus because the two cannot always be discriminated, and Heyn (1970a), in the Flora of Turkey, took the same position. Although U.S. populations of L. corniculatus differ in habit and leaflet proportions, they are much less diverse than those in Europe, and present no taxonomic problems save the differentiation of L. tenuis as noted above. The classification of related experimental introductions is uncertain. Ball and Chrtkova-Zertova (1968) listed 12 binomials among the “L. corniculatus group,” stating that they were uncertain which should be considered species. Grant and students, in several publications (e.g., Grant, 1965), regarded most segregates as species. In the most recent revision of L. corniculatus (Chrtkova-Zertova, 1973; “central and northern Europe”), L. corniculatus was defined as a polymorphic, tetraploid species including 14 varieties within the geographic area studied. Lotus corniculatus as provisionally defined herein is equivalent to the tetraploid elements of Ball and Chrtkova-Zertova’s (1968) complex. Possibly these tetra-ploids include several species. For example, Harney and Grant (1964a), on the data, treat L. caucasicus at the specific level and it is so listed in U.S.D.A. PI introductions. My listing of L. caucasicus as a synonym must be regarded as nolle prosequi. Birdsfoot trefoil, one of the most important forage legumes in the world is grown in the United States on more than 2 million acres, primarily in the northeastern and north-central states, and the cismontane Pacific. Of high nutritive value, it is more tolerant of acid, infertile and poorly drained soils than other forage legumes, and has replaced much red and white clover, and timothy in the east. It is a common component of permanent pastures in the central states. It does not cause bloat, a common danger from alfalfa and the clovers. Usually produced in mixtures with grasses, it may be grazed, or cut for hay or silage. Its limitations are of stand establishment and susceptibility to diseases in hot, humid climates. Agronomic kinds include several recently developed cultivars. Since the entry of birdsfoot trefoil into American agriculture is relatively recent, the still useful classic study is that of MacDonald (1946). Recent literature is cited by Seaney (1974) in Heath et al. (1974), and by authors of other books or papers on forages. The Lotus Newsletter (editor, W. F. Grant, Genetics Laboratory, MacDonald Campus of McGill University, Quebec, Canada) provides continuing reference to current publications.
Distribution:
United States of America North America| Europe| Asia|
United States of America North America| Europe| Asia|