Lotus L.

Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

Note

The Loteae have been usually considered as the closest relatives of other temperate tribes, especially of the astragaloid part of Galegeae (e.g., Polhill, 1981k: 371–374), and the monospecific genus Podolotus was either allied with Lotus, or merged with Astragalus. Recent molecular data, however, have revealed that Galegeae, Cicereae, Hedysareae, Trifolieae, Fabeae and Millettieae (in small part) lack the chloroplast-DNA inverted repeat (IR) which is present in the majority of Leguminosae including Loteae (Liston, 1995). A study of the chloroplast gene rbcL also placed Loteae and other temperate tribes in different clades (Doyle et al., 1997), the Loteae being in a robinioid clade and the temperate tribes in an Inverted Repeat Lacking clade (IRLC). In recent supertrees of the Hologalegina alliance (Wojciechowski et al., 2000, 2004), Loteae sens. lat. are sister to Sesbania, and the combined Loteae-Sesbanieae clade is itself sister to the Robinieae.

Loteae differ from Robinieae in a suite of characters which were listed by Dormer (1945) for his ‘epulvinate series’, i.e., often herbaceous habit and leaves mostly distichous, usually without a pulvinus. These characters are now of less phylogenetic importance since the ‘epulvinate series’ is no longer considered to be a monophyletic group. An obvious synapomorphy of Loteae, shared by all extant members of the tribe, is stamen filaments dilated upwards. This is an adaptation for secondary pollen presentation. Another apomorphy shared by almost all Loteae is the capitate or umbellate partial inflorescence, while Robinieae possesses racemes. A most unusual (and possibly synapomorphic) morphological character of many Loteae is the presence of a foliage leaf on the peduncle. This leaf is often described as a bract, but it has neither a flower nor other structures in its axil. True bracts in Loteae usually lack a blade and are membranous or glandular. Phylogenetic evidence suggests the presence or absence of the foliage leaf on the peduncle is homoplastic within Loteae.

The circumscription of Loteae has recently been expanded to include genera formerly placed in Coronilleae (Polhill, 1981k & l; 1994). These two tribes were previously distinguished by the lomentaceous fruits and branched root nodules in Coronilleae (fruits non-lomentaceous and root nodules unbranched in Loteae sens. strict.). The Coronilleae were earlier placed in tribe Hedysareae (Bentham, 1865) because of their lomentaceous fruits.

The merging of Loteae sens. strict. and Coronilleae is supported by both morphological (Polhill, 1981k; Lassen, 1989; Díez & Ferguson, 1990, 1994, 1996; Tikhomirov & Sokoloff, 1996a) and molecular data (Doyle, 1995; Liston, 1995; Doyle et al., 1997; Allan, 1998; Allan & Porter, 2000; Allan et al., 2003). These data indicate that lomentaceous fruits have arisen independently in Coronilleae and Hedysareae, and perhaps even in different genera of Coronilleae. Allan & Porter (2000: Fig. 2A) suggested, however, that lomentaceous fruits were a plesiomorphic condition for Loteae sens. lat. In our opinion, an ancestor of Loteae might have had dehiscent fruits divided into regular compartments by thin transverse septa (as in Sesbania and Lotus sens. lat.). The genera formerly placed in Coronilleae do not form a natural taxonomic unit at any level. Regarding fruit anatomy, lomentaceous fruits of Securigera and Coronilla are related to dehiscent fruits in the Lotus group, while lomentaceous fruits of Ornithopus and Antopetitia share important features of pericarp structure with the indehiscent non-lomentaceous fruits of Anthyllis and Dorycnopsis.

Recent publications have led to the removal of some groups from Lotus sens. lat. (Lassen, 1986; Tikhomirov & Sokoloff, 1997; Sokoloff, 1999, 2000), Coronilla sens. lat. (Lassen, 1989) and Anthyllis sens. lat. (Lassen, 1986; Tikhomirov & Sokoloff, 1996a, 1997). Morphological and molecular data relevant to the relationships between Old World and New World Loteae have recently been published (Díez & Ferguson, 1990, 1994, 1996; Kramina & Sokoloff, 1997a; Allan, 1998; Allan & Porter, 2000; Allan et al., 2000, 2002, 2003; Degtjareva et al., 2003). The placement of Podolotus in Loteae is now well supported by morphological data. Allan & Porter (2000) and Allan et al. (2003), using nuclear ribosomal ITS, concluded that Old World and New World Lotus sens. lat. belong to distinct clades. In the latter analysis, Old World Lotus forms a moderately supported monophyletic group if Tetragonolobus and Dorycnium are included, while New World Lotus is paraphyletic, also containing the Old World Ornithopus (although with 1 sp. in the New World) and Kebirita among others. In this treatment Loteae is considered to comprise 22 genera and c. 282 species (Fig. 51).

Polhill (1981k) adopted a broad concept of the genus, but Lassen (1986) and Sokoloff (1999, 2000) accepted a number of segregates; the American species are treated here under Hosackia, Ottleya, Acmispon and Syrmatium (Sokoloff, 1999); the genus is taxonomically difficult at specific as well as at sectional and subgeneric levels; several species are extremely variable, e.g., L. corniculatus L. and L. australis Andr., and hybridisation is frequent

Habit

Herbs, suffrutices and shrubs

Ecology

Temperate, mediterranean, subtropical and tropical montane grassland and shrubland, desert and disturbed places

Distribution

N Temperate; here treated as exclusively Old World, mainly Europe, Mediterranean (including N Africa) and Macaronesia, eastwards to C, SW and E Asia (S and W Siberia, Mongolia, Himalaya, China, Korea and Japan); c. 2 spp. endemic to Australia and 1 sp. to New Caledonia and Vanuatu, and c. 20 spp. in mostly montane tropical to Somalia-Masai regions in Africa and Arabia

Leguminosae, various authors. Flora Zambesiaca 3:7. 2003

Morphology General Habit

Annual or perennial herbs, subshrubs or dwarf shrubs.

Morphology Leaves

Leaves sessile or with a very short petiole, usually with 5, rarely with 3–4, leaflets (or elsewhere occasionally more); leaflets petiolulate, the lower pair at the base of the rhachis and resembling stipules; stipules reduced to dark glands, sometimes inconspicuous, or absent; stipels absent.

Morphology Reproductive morphology Flowers

Flowers in axillary usually pedunculate umbels with a 1–3-foliolate foliage leaf, rarely umbels reduced to one flower and resembling solitary flowers.

Morphology Reproductive morphology Flowers Calyx

Calyx tubular or narrowly campanulate, subequally 5-toothed or the lowest tooth longest or the teeth in 2 lips.

Morphology Reproductive morphology Flowers Corolla

Corolla yellow, pink, cream or white, glabrous or rarely (in Macaronesia and Morocco) the standard and (very rarely) also the wings pubescent, free from the stamens; standard ± oblong-obovate, wedge-shaped at the base with infolded thickened margins; wings clawed, the blade oblong, auriculate, laterally pouched; keel curved, pointed or beaked with free claws.

Morphology Reproductive morphology Flowers Androecium Stamens

Vexillary stamen free, the other 9 with the filaments united into a sheath; free parts of at least the 5 longer filaments widened at the tip.

Morphology Reproductive morphology Flowers Gynoecium Pistil

Ovary sessile or shortly stipitate, glabrous (outside the Flora Zambesiaca area sometimes strigulose or hairy), subcylindrical, multi-ovulate; style bent upwards at the base, glabrous, but papillose, rigid.

Morphology Reproductive morphology Fruits

Pod usually cylindrical, straight, linear, usually septate within, dehiscent into 2 valves (except in L. benoistii, from Morocco, with an indehiscent fruit, and in the Mediterranean L. edulis with the fruit dehiscent ventrally), the valves often becoming twisted.

Morphology Reproductive morphology Seeds

Seeds ellipsoid, subreniform or subglobular, with a small, median hilum.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Herbs or softly woody shrublets

Morphology Leaves

Leaves imparipinnate or digitate, (3–)5-foliolate, the lowest pair resembling stipules; stipules minute

Morphology Reproductive morphology Inflorescences

Flowers in pedunculate heads or umbels, or rarely solitary

Morphology Reproductive morphology Flowers Calyx

Calyx subequally 5-toothed or rarely 2-lipped

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Upper filament free, the other 9 united

Morphology Reproductive morphology Fruits

Pod straight, usually cylindrical, dehiscent, many-seeded.

Distribution

Old World genus of some 120-130 species, widespread, most numerous around the Mediterranean.

Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

Habit

Herbs

Ecology

Mediterranean and warm temperate grassland

Distribution

Mainly Mediterranean to E Europe and Caucasus

Note

Close to Lotus and often considered a section of it; Tetragonolobus can easily be separated from Lotus by fruit, style and leaf morphology, but the phylogenies of Allan & Porter (2000) and Allan et al. (2003), and Sokoloff (2003a) indicate that Tetragonolobus is firmly embedded within Lotus

The Loteae have been usually considered as the closest relatives of other temperate tribes, especially of the astragaloid part of Galegeae (e.g., Polhill, 1981k: 371–374), and the monospecific genus Podolotus was either allied with Lotus, or merged with Astragalus. Recent molecular data, however, have revealed that Galegeae, Cicereae, Hedysareae, Trifolieae, Fabeae and Millettieae (in small part) lack the chloroplast-DNA inverted repeat (IR) which is present in the majority of Leguminosae including Loteae (Liston, 1995). A study of the chloroplast gene rbcL also placed Loteae and other temperate tribes in different clades (Doyle et al., 1997), the Loteae being in a robinioid clade and the temperate tribes in an Inverted Repeat Lacking clade (IRLC). In recent supertrees of the Hologalegina alliance (Wojciechowski et al., 2000, 2004), Loteae sens. lat. are sister to Sesbania, and the combined Loteae-Sesbanieae clade is itself sister to the Robinieae.

Loteae differ from Robinieae in a suite of characters which were listed by Dormer (1945) for his ‘epulvinate series’, i.e., often herbaceous habit and leaves mostly distichous, usually without a pulvinus. These characters are now of less phylogenetic importance since the ‘epulvinate series’ is no longer considered to be a monophyletic group. An obvious synapomorphy of Loteae, shared by all extant members of the tribe, is stamen filaments dilated upwards. This is an adaptation for secondary pollen presentation. Another apomorphy shared by almost all Loteae is the capitate or umbellate partial inflorescence, while Robinieae possesses racemes. A most unusual (and possibly synapomorphic) morphological character of many Loteae is the presence of a foliage leaf on the peduncle. This leaf is often described as a bract, but it has neither a flower nor other structures in its axil. True bracts in Loteae usually lack a blade and are membranous or glandular. Phylogenetic evidence suggests the presence or absence of the foliage leaf on the peduncle is homoplastic within Loteae.

The circumscription of Loteae has recently been expanded to include genera formerly placed in Coronilleae (Polhill, 1981k & l; 1994). These two tribes were previously distinguished by the lomentaceous fruits and branched root nodules in Coronilleae (fruits non-lomentaceous and root nodules unbranched in Loteae sens. strict.). The Coronilleae were earlier placed in tribe Hedysareae (Bentham, 1865) because of their lomentaceous fruits.

The merging of Loteae sens. strict. and Coronilleae is supported by both morphological (Polhill, 1981k; Lassen, 1989; Díez & Ferguson, 1990, 1994, 1996; Tikhomirov & Sokoloff, 1996a) and molecular data (Doyle, 1995; Liston, 1995; Doyle et al., 1997; Allan, 1998; Allan & Porter, 2000; Allan et al., 2003). These data indicate that lomentaceous fruits have arisen independently in Coronilleae and Hedysareae, and perhaps even in different genera of Coronilleae. Allan & Porter (2000: Fig. 2A) suggested, however, that lomentaceous fruits were a plesiomorphic condition for Loteae sens. lat. In our opinion, an ancestor of Loteae might have had dehiscent fruits divided into regular compartments by thin transverse septa (as in Sesbania and Lotus sens. lat.). The genera formerly placed in Coronilleae do not form a natural taxonomic unit at any level. Regarding fruit anatomy, lomentaceous fruits of Securigera and Coronilla are related to dehiscent fruits in the Lotus group, while lomentaceous fruits of Ornithopus and Antopetitia share important features of pericarp structure with the indehiscent non-lomentaceous fruits of Anthyllis and Dorycnopsis.

Recent publications have led to the removal of some groups from Lotus sens. lat. (Lassen, 1986; Tikhomirov & Sokoloff, 1997; Sokoloff, 1999, 2000), Coronilla sens. lat. (Lassen, 1989) and Anthyllis sens. lat. (Lassen, 1986; Tikhomirov & Sokoloff, 1996a, 1997). Morphological and molecular data relevant to the relationships between Old World and New World Loteae have recently been published (Díez & Ferguson, 1990, 1994, 1996; Kramina & Sokoloff, 1997a; Allan, 1998; Allan & Porter, 2000; Allan et al., 2000, 2002, 2003; Degtjareva et al., 2003). The placement of Podolotus in Loteae is now well supported by morphological data. Allan & Porter (2000) and Allan et al. (2003), using nuclear ribosomal ITS, concluded that Old World and New World Lotus sens. lat. belong to distinct clades. In the latter analysis, Old World Lotus forms a moderately supported monophyletic group if Tetragonolobus and Dorycnium are included, while New World Lotus is paraphyletic, also containing the Old World Ornithopus (although with 1 sp. in the New World) and Kebirita among others. In this treatment Loteae is considered to comprise 22 genera and c. 282 species (Fig. 51).

Legumes of the World. Edited by G. Lewis, B. Schrire, B. MacKinder & M. Lock. Royal Botanic Gardens, Kew. (2005)

Habit

Shrubs, suffrutices or herbs

Ecology

Mediterranean woodland and shrubland, dry slopes; D. strictum (Fisch. & C.A.Mey.) Lassen often in saline habitats

Distribution

C, S and E Europe, mainly Mediterranean, eastwards to Caucasus and W Asia (Iran)

Note

A generally accepted genus, but limits much disputed; corrections to Rikli's (1901) monograph should be: 1) transfer Anthyllis fulgurans Porta and Lotus strictus Fisch. & C.A.Mey. to Dorycnium (Lassen, 1979; 1986); 2) transfer Dorycnium sect. Canaria Rikli to Lotus, as a subgenus (Gillett, 1959); the basic distinction of Dorycnium from Lotus is the smooth (not papillose) style; further studies may show that Lotus and Dorycnium should be merged, as proposed by Polhill (1981k) and as indicated in the phylogeny of Allan et al. (2003); Sokoloff (2003a) transferred all species of Dorycnium to Lotus; the D. pentaphyllum Scop. complex is very variable and problematic

The Loteae have been usually considered as the closest relatives of other temperate tribes, especially of the astragaloid part of Galegeae (e.g., Polhill, 1981k: 371–374), and the monospecific genus Podolotus was either allied with Lotus, or merged with Astragalus. Recent molecular data, however, have revealed that Galegeae, Cicereae, Hedysareae, Trifolieae, Fabeae and Millettieae (in small part) lack the chloroplast-DNA inverted repeat (IR) which is present in the majority of Leguminosae including Loteae (Liston, 1995). A study of the chloroplast gene rbcL also placed Loteae and other temperate tribes in different clades (Doyle et al., 1997), the Loteae being in a robinioid clade and the temperate tribes in an Inverted Repeat Lacking clade (IRLC). In recent supertrees of the Hologalegina alliance (Wojciechowski et al., 2000, 2004), Loteae sens. lat. are sister to Sesbania, and the combined Loteae-Sesbanieae clade is itself sister to the Robinieae.

Loteae differ from Robinieae in a suite of characters which were listed by Dormer (1945) for his ‘epulvinate series’, i.e., often herbaceous habit and leaves mostly distichous, usually without a pulvinus. These characters are now of less phylogenetic importance since the ‘epulvinate series’ is no longer considered to be a monophyletic group. An obvious synapomorphy of Loteae, shared by all extant members of the tribe, is stamen filaments dilated upwards. This is an adaptation for secondary pollen presentation. Another apomorphy shared by almost all Loteae is the capitate or umbellate partial inflorescence, while Robinieae possesses racemes. A most unusual (and possibly synapomorphic) morphological character of many Loteae is the presence of a foliage leaf on the peduncle. This leaf is often described as a bract, but it has neither a flower nor other structures in its axil. True bracts in Loteae usually lack a blade and are membranous or glandular. Phylogenetic evidence suggests the presence or absence of the foliage leaf on the peduncle is homoplastic within Loteae.

The circumscription of Loteae has recently been expanded to include genera formerly placed in Coronilleae (Polhill, 1981k & l; 1994). These two tribes were previously distinguished by the lomentaceous fruits and branched root nodules in Coronilleae (fruits non-lomentaceous and root nodules unbranched in Loteae sens. strict.). The Coronilleae were earlier placed in tribe Hedysareae (Bentham, 1865) because of their lomentaceous fruits.

The merging of Loteae sens. strict. and Coronilleae is supported by both morphological (Polhill, 1981k; Lassen, 1989; Díez & Ferguson, 1990, 1994, 1996; Tikhomirov & Sokoloff, 1996a) and molecular data (Doyle, 1995; Liston, 1995; Doyle et al., 1997; Allan, 1998; Allan & Porter, 2000; Allan et al., 2003). These data indicate that lomentaceous fruits have arisen independently in Coronilleae and Hedysareae, and perhaps even in different genera of Coronilleae. Allan & Porter (2000: Fig. 2A) suggested, however, that lomentaceous fruits were a plesiomorphic condition for Loteae sens. lat. In our opinion, an ancestor of Loteae might have had dehiscent fruits divided into regular compartments by thin transverse septa (as in Sesbania and Lotus sens. lat.). The genera formerly placed in Coronilleae do not form a natural taxonomic unit at any level. Regarding fruit anatomy, lomentaceous fruits of Securigera and Coronilla are related to dehiscent fruits in the Lotus group, while lomentaceous fruits of Ornithopus and Antopetitia share important features of pericarp structure with the indehiscent non-lomentaceous fruits of Anthyllis and Dorycnopsis.

Recent publications have led to the removal of some groups from Lotus sens. lat. (Lassen, 1986; Tikhomirov & Sokoloff, 1997; Sokoloff, 1999, 2000), Coronilla sens. lat. (Lassen, 1989) and Anthyllis sens. lat. (Lassen, 1986; Tikhomirov & Sokoloff, 1996a, 1997). Morphological and molecular data relevant to the relationships between Old World and New World Loteae have recently been published (Díez & Ferguson, 1990, 1994, 1996; Kramina & Sokoloff, 1997a; Allan, 1998; Allan & Porter, 2000; Allan et al., 2000, 2002, 2003; Degtjareva et al., 2003). The placement of Podolotus in Loteae is now well supported by morphological data. Allan & Porter (2000) and Allan et al. (2003), using nuclear ribosomal ITS, concluded that Old World and New World Lotus sens. lat. belong to distinct clades. In the latter analysis, Old World Lotus forms a moderately supported monophyletic group if Tetragonolobus and Dorycnium are included, while New World Lotus is paraphyletic, also containing the Old World Ornithopus (although with 1 sp. in the New World) and Kebirita among others. In this treatment Loteae is considered to comprise 22 genera and c. 282 species (Fig. 51).