Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 5, 1996
Publication Date: N/A
Interpretive Summary: The vascular plant genus Lotus includes bird's-foot trefoil and is the fourth most common important forage legume in the United States. The number of species included in Lotus has varied over time with several smaller genera recently recognized as distinct from Lotus. Knowledge of the relationships among species of Lotus and closely related genera is needed in order to determine what plant germplasm can serve as a possible source in breeding for improved forage crops. This paper provides an account of the 172 species that have been included in Lotus and their characteristics. Using this information it is possible to locate plant germplasm that has potential for producing "designer" forage crops.
The genus Lotus consists of 172 species; a list of the species is presented. Of this total, 48 species are known only from the New World, and 124 from the Old World. It is most species rich in regions with Mediterranean climate, i.e., the Mediterranean basin and the far western United States and northwestern Mexico. It occurs throughout the continents sof Africa, Europe, Asia, Australia, and North America, is abundant in Macaronesia, and is represented in both northern Central America and Chile by single species. Lotus species recognized in the Old World are more narrowly defined than those recognized in the New World. The large number of species in the Old World is partially attributable to this. Most twentieth century Old World Lotus taxonomists have defined Lotus species narrowly, with some notable exceptions, and can, in general, be referred to as "splitters." Twentieth century New World Lotus taxonomists have delimited species more broadly, and, in general, can be referred to as "lumpers." The most economically important species are described, and a key is given for their identification.