Cytotaxonomic Studies in the Leguminosae

1. Seventy-nine species from fifty-five genera representative of the three subfamilies of the family Leguminosae were studied. 2. In the subfamily Mimosoideae, in all species studied polyploid divisions occurred at the beginning of the mitotic activity in the root meristem. As the seedlings increased in length these divisions decreased in number. 3. In the subfamily Caesalpinioideae, polyploid divisions were found early in development of Delonyx, Cassia and Parkinsonia. Polyploid divisions were not found in Cercis chinensis, Bauhinia purpurea, Bauhinia tomentosa, Bauhinia ungulata, Bauhinia variegata, Ceratonia siliqua, Dialium indica, Erythrophloem guineense, Sinodora bruggenanmide, Trachylobium verrucosum, Peltogyne paniculata, Hymenaea courbaril, Intsia bijuga, Gymnocladus dioica, Gleditsia triacanthos, Peltophorum inerme, Caesalpinia granadillo, C. pulcherrima, C. sappan. 4. In the subfamily Papilionoideae, polyploid divisions were found in the root meristem of young seedlings of only a single genus, Aeschynomene. Sufficient seeds, however, could not be obtained for a detailed study. 5. It is suggested that the presence or absence of polyploid divisions in the development of diploid species may be a new and useful criterion for taxonomic studies.