Chromosome Numbers in Compositae. IX. Haplopappus and Other Astereae

Abstract

Reports of 209 original chromosome counts are made for the tribe Astereae of Compositae, including first counts for two genera and 46 species or subspecies. With over 80 % of the species counted, chromosome numbers are now available for all North American sections of Haplopappus. Two major groupings are apparent: one, with basic numbers of x = 4, 5, or 6, is basically herbaceous; the other, with x = 9, consists of shrubs or subshrubs. Aneuploidy is known only in the “herbaceous” group of Haplopappus, and polyploidy is more extensive there than in the woodier group of sections.