About Flowering Biology of Alien Species: 3. Caragana arborescensLam. and C. laetaKom.

Some data on flowering biology of a potentially aggressive alien species—Caragana arborescens—are presented. Micromorphological characters of flowers at different stages of development for typical plants and two cultivars (C. arborescensf. pendulaand C. arborescensf. lorbergii) and also for the Central Asian C. laetaare described. The pollen fertility is defined. A number of features in which C. arborescenshas a competitive superiority over closely related taxa are revealed. Arguments for C. arborescensf. lorbergiiallocation as a particular taxon are adduced.