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 - Procumbent or ascending, usually glabrate (-pubescent) perennials with clustered stems .4-5 dm of superficial origin from a tap root. Leaves of edentolotus type; leafstalk 2-6 mm; leaflets lanceolate to linear, .6-2.5 cm, 2.5-7 r. Stipules obsolete. Umbels strongly peduncled, immediately subtended by an inconspicuous, usually trifoliolate bract; flowers 1-5, 8—10(—12) mm, ascending to horizontal. Calyx tube obconic, 1.8-2.8 mm; teeth subulate, ± tube. Corolla yellow, fading orange, frequently dull blue-tipped on dry specimens, 8-12 mm (or in L. borbasii, to 18 mm), regularly graduated; keel lunate, acuminate-porrect. Stamens of alternating lengths. Ovary with 20-40 ovules; style defined, geniculate. Legumes corniculate, terete, 1-2 cm x ca. 2 mm. Seeds many.
Species Description - Procumbent or ascending, usually glabrate (-pubescent) perennials with clustered stems .4-5 dm of superficial origin from a tap root. Leaves of edentolotus type; leafstalk 2-6 mm; leaflets lanceolate to linear, .6-2.5 cm, 2.5-7 r. Stipules obsolete. Umbels strongly peduncled, immediately subtended by an inconspicuous, usually trifoliolate bract; flowers 1-5, 8—10(—12) mm, ascending to horizontal. Calyx tube obconic, 1.8-2.8 mm; teeth subulate, ± tube. Corolla yellow, fading orange, frequently dull blue-tipped on dry specimens, 8-12 mm (or in L. borbasii, to 18 mm), regularly graduated; keel lunate, acuminate-porrect. Stamens of alternating lengths. Ovary with 20-40 ovules; style defined, geniculate. Legumes corniculate, terete, 1-2 cm x ca. 2 mm. Seeds many.
Discussion:
Cultivated Lotus cormculatus var tenuifolius L. (1753); L. tenuifolius (L.) Reichenb. (1832). L. tenuis Waldst. & Kit. ex Willd. (1809). L. alpinus (DC.) Schleich. ex Ramond (1825). L.filicaulis Durieu (1847). L. glareosus Boiss. & Reuter (1852). L. schoelleri Schweinf. (18%). L. krylovii Schischk. & Serg. (1932). L.frondosus (Freyn) Kupr. (1945). L.japonicus (Regel) Larsen (1955). L. borbasii Ujhelyi (1960). L. burtii Sz-Borsos (1972). L. corniculatus auct. pro parte. CN In = 12 (Grant, 1965; and many others). Among established Lotus, Lotus tenuis is distinguished, not always exactly, from the much commoner L. corniculatus by its narrower leaflets and slightly smaller, usually fewer flowers. Although treated at the specific level by Isely (1951), most U.S. manuals have reduced it to synonymy under L. corniculatus. Indeed, most European botanists (e.g., Heyn, 1970a; Gillett, 1958), except for the Russians (e.g., Kupriyanova, 1945), have adopted the same view. This, I think, is because the exomorphic distinctions among these plants are trivial and overlapping. The Lotus tenuis group, as defined by the above description, comprises the diploid members of the L. corniculatus complex sensu Ball and Chrtkova-Zertova (1968), except for L. palustris Willd. that seems best associated with L. angus-tissimus (Heyn, 1970a, 1970b). The synonyms represent members of this group that have been introduced into the Western Hemisphere for experimental purposes. Most of them, as L. tenuis, differ from L. corniculatus either in having narrow leaflets, or only 1-2, commonly smaller flowers per umbel, but these distinctions are not consistently valid; e.g., L. borbasii and L. krylovii also are listed separately because they do not key with the rest of the group. For distinctions among these plants, the best reference is possibly the Ball and Chrktova-Zertova (1968) “Key to the Lotus corniculatus group.” Larsen (e.g., Larsen and Zertova, 1963, with citations to earlier papers) has studied European Lotus cytotaxonomically, and Grant and coworkers have assembled extensive cytogenetic, cross-compatibility, morphological, and chemical data about the L. tenuis and L. corniculatus groups; e.g., Cheng and Grant (1973), Somaroo and Grant (1972), Harney and Grant (1965), and Grant (1965). Grant et al. have clearly established, I think, that the tetraploids and diploids constitute different species or groups of species. The unity of the diploids, the L. tenuis group, is suggested by the morphological, chemical, and cytological similarity of most of the members and by the fact that many are apparently geographic replacements of one another. The difficulty of this concept in practice is simply that the L. tenuis and L. corniculatus groups cannot be consistently identified by exomorphic characters. Hence, in the United States, L. tenuis is usually treated as a quasi-distinguishable variety of L. corniculatus. In Japan, where L. japonicus (Regel) Larsen, a diploid, is native, some herbarium material identified as that species is the introduced European tetraploid L. corniculatus. Within the Lotus tenuis group, Grant (e.g., 1965) lists numerous species, as does Kupriyanova (1945). I believe Grant and colleagues have failed to make a satisfactory case for their taxonomic concepts. Nowhere are the data synthesized into a coherent whole nor evaluated in relation to the exomorphic, ecological and geographic characters of the elements. The sampling, limited too often to relatively few introductions, is commonly inadequate. For example, Nettancourt and Grant (1963) contrasted L. tenuis and L. filieaulis on the basis of detailed mathematical tabulations that, however, were seemingly derived from the progeny of only one introduction entry for each species. Nowhere, except in Zandstra and Grant (1968), are taxa defined comparatively by keys and descriptions, and that paper lists only two members of L. tenuis affiliation. A critical revisionary study, probably from a European base, is still needed for the diploid taxa related to L. tenuis.
Cultivated Lotus cormculatus var tenuifolius L. (1753); L. tenuifolius (L.) Reichenb. (1832). L. tenuis Waldst. & Kit. ex Willd. (1809). L. alpinus (DC.) Schleich. ex Ramond (1825). L.filicaulis Durieu (1847). L. glareosus Boiss. & Reuter (1852). L. schoelleri Schweinf. (18%). L. krylovii Schischk. & Serg. (1932). L.frondosus (Freyn) Kupr. (1945). L.japonicus (Regel) Larsen (1955). L. borbasii Ujhelyi (1960). L. burtii Sz-Borsos (1972). L. corniculatus auct. pro parte. CN In = 12 (Grant, 1965; and many others). Among established Lotus, Lotus tenuis is distinguished, not always exactly, from the much commoner L. corniculatus by its narrower leaflets and slightly smaller, usually fewer flowers. Although treated at the specific level by Isely (1951), most U.S. manuals have reduced it to synonymy under L. corniculatus. Indeed, most European botanists (e.g., Heyn, 1970a; Gillett, 1958), except for the Russians (e.g., Kupriyanova, 1945), have adopted the same view. This, I think, is because the exomorphic distinctions among these plants are trivial and overlapping. The Lotus tenuis group, as defined by the above description, comprises the diploid members of the L. corniculatus complex sensu Ball and Chrtkova-Zertova (1968), except for L. palustris Willd. that seems best associated with L. angus-tissimus (Heyn, 1970a, 1970b). The synonyms represent members of this group that have been introduced into the Western Hemisphere for experimental purposes. Most of them, as L. tenuis, differ from L. corniculatus either in having narrow leaflets, or only 1-2, commonly smaller flowers per umbel, but these distinctions are not consistently valid; e.g., L. borbasii and L. krylovii also are listed separately because they do not key with the rest of the group. For distinctions among these plants, the best reference is possibly the Ball and Chrktova-Zertova (1968) “Key to the Lotus corniculatus group.” Larsen (e.g., Larsen and Zertova, 1963, with citations to earlier papers) has studied European Lotus cytotaxonomically, and Grant and coworkers have assembled extensive cytogenetic, cross-compatibility, morphological, and chemical data about the L. tenuis and L. corniculatus groups; e.g., Cheng and Grant (1973), Somaroo and Grant (1972), Harney and Grant (1965), and Grant (1965). Grant et al. have clearly established, I think, that the tetraploids and diploids constitute different species or groups of species. The unity of the diploids, the L. tenuis group, is suggested by the morphological, chemical, and cytological similarity of most of the members and by the fact that many are apparently geographic replacements of one another. The difficulty of this concept in practice is simply that the L. tenuis and L. corniculatus groups cannot be consistently identified by exomorphic characters. Hence, in the United States, L. tenuis is usually treated as a quasi-distinguishable variety of L. corniculatus. In Japan, where L. japonicus (Regel) Larsen, a diploid, is native, some herbarium material identified as that species is the introduced European tetraploid L. corniculatus. Within the Lotus tenuis group, Grant (e.g., 1965) lists numerous species, as does Kupriyanova (1945). I believe Grant and colleagues have failed to make a satisfactory case for their taxonomic concepts. Nowhere are the data synthesized into a coherent whole nor evaluated in relation to the exomorphic, ecological and geographic characters of the elements. The sampling, limited too often to relatively few introductions, is commonly inadequate. For example, Nettancourt and Grant (1963) contrasted L. tenuis and L. filieaulis on the basis of detailed mathematical tabulations that, however, were seemingly derived from the progeny of only one introduction entry for each species. Nowhere, except in Zandstra and Grant (1968), are taxa defined comparatively by keys and descriptions, and that paper lists only two members of L. tenuis affiliation. A critical revisionary study, probably from a European base, is still needed for the diploid taxa related to L. tenuis.
Distribution:
Europe| Asia| Africa| United States of America North America|
Europe| Asia| Africa| United States of America North America|