Genus Medicago (Leguminosae)

In introducing ourselves it should be told that in our native Latvian language our name is written LesiJ;l. s. In most English publications, as in this work, the writing has been simplified to Lesins, and often only the first initial has been used. Our interest in Medicago was first aroused during 1936-38, while em ployed as teachers in the agricultural and home economics school at Be brene, Upper Zemgale, Latvia. Some plants of alfalfa (M. varia, M. media), locally called 'lucema', were found growing wild along roadsides in that area, though no alfalfa fields had been seen in the vicinity within the me mory of local farmers. Some roadside plants were dug out and transplanted to the garden, but their seedset was poor. During the next few years we paid only slight attention to alfalfa, the reason being that Latvia is a country with Atlantic climatic features (annual precipitation 600-700 mm; mild win ters for its 56°-58° N. Lat. , with January isotherms between -3° and -7° C; moderately warm summers, with July isotherms between 16° and 18° C), which together with its soils, mostly of acidic, podzolic type, is not well suited for alfalfa production. It was not until 1945 in Sweden that work on alfalfa came to the foreground, when the senbor author was assigned investi gations on alfalfa seed setting by Dr. Erik Akerberg, then director of the Swedish Seed Association branch station at ffituna.

Contenu
General Part.- Procedural.- Notes to Items of Specific Part.- Habitat and Distribution.- Intraspecific Variations, Distinguishing Features Between and Relationship to Other Species.- Agricultural Value.- Isolating Mechanisms, Speciation, Evolution in Medicago, Relationship to Other Genera.- Factors in Speciation, General.- Evolution in Medicago.- Relationship to Other Genera.- Specific Part.- Genus Medicago, and Key to Subgenera.- General Key to Medicago Species.- References.- Index to plant genera, sections, species and hybrids not listed in contents.