Corrections of the Chromosome Number, Distribution and Misidentifications of the Federally Endangered Sunflower, Helianthus schweinitzii T&G

Abstract

MATTHEWS, J. F., L. S. BARDEN AND C. R. MATTHEWS (Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223). Corrections of the chromosome number, distribution and misidentifications of the Federally endangered sunflower, Helianthus schweinitzii T&G. Torrey Bot. Soc. 124:198-209. 1997.Helianthus schweintizii was designated as a Federally endangered species in 1991. Since that time, an intensive research effort has been carried out on the species. The taxonomic typification is clarified through the examination of all the pertinent material. Examination of the historical background of Lewis David von Schweinitz allows a theory of the location of the original collection site. Misidentifications of the species before it was well known produced incorrect distributions and led to a report of chemical compounds attributed to this species, but which in fact occur in another sunflower. These identifications are corrected. The reported chromosome number of n = 51 (hexaploid), based on one collection that cannot be relocated, is corrected to 2n = 68 (tetraploid), based on 33 counts from eight populations.