Aster and Brachyactis in Illinois

Abstract

The need for a comprehensive study and taxonomic revision of asters in Illinois becomes apparent when one looks at the varied treatments of this genus in the principal floristic literature of the state (G.N. Jones 1945, 1950, 1963; Jones and Fuller 1935: Mohlenbrock 1975. 1986; Mohlenbrock and Ladd 1978. Three factors contribute to the differences found in these works: the number of taxa recorded for Illinois, nomenclatural considerations such as those dictated by the principle of priority, and differences in taxonomic concepts and interpretations. In the first edition of Flora of Illinois (G.N. Jones 1945). 33 species are treated under Aster, not counting hybrids. Three additional species appear in the third edition (G.N. Jones 1963): A. chasei G.N. Jones in Jones & Fuller, a species newly described from Illinois: A. tartaricus L.f.. an occasionally escaped cultivated species; and A.parviveps (Burgess in Britton & Brown) Mack. & Bush, probably inadvertently omitted from the first two editions but included in Jones and Fuller (1955). In the most recent (Guide to the Vascular Flora of Illinois. Mohlenbrock (1986) treats 35 species. A notable change involves the transfer of A. ptarmicoides (Nees) Torrey & Gray to Solidago. In this revision, I recognize 31 species of Aster in the state of Illinois. My research has concentrated on New World and some Old World species of Aster (sensu lato) forever 15 years (A.G. Jones 1974, 1977, 1978a, b, c. I980a, b, 1982, 1983,1984, 1987; Jones and Hiepko 1981; Jones and Young 1983; Jones and Lowry 1986; and others), and much additional infomation has been introduced in this current study. My taxonomic concepts are summarized in the conspectus of classification of Illinois Aster species.