A biosystematic investigation was undertaken in 15
species and three subspecies of the genus Aster, in western
North America. Previous studies had been based entirely on
external morphological features, and it was believed that
much could be learned about the natural affinities of the
taxa by exploring their cytological and...
A study consisting of three parts was undertaken to investigate how variation in species interactions, population genetic structure, epidemiological parameters, and plant breeding system may influence the ecology and biological control of an apomictic invasive plant, Chondrilla juncea (Asteraceae). Interactions between natural enemy species may modify their net effect on...