Chromosome Numbers and Evolution in Anoda and Periptera (Malvaceae)

Relationships within and between the principally North American, malvaceous genera A noda and Periptera are assessed through analysis of chromosomal and hybridization data. Chromosome numbers are reported for ten species of Anoda and one of Periptera, and observations on meiosis in hybrid and non hybrid plants are presented . The results indicate: I) that Anoda and Periptera are closely related and occupy a relatively isolated position in the tribe Malveae, 2) that speciation in A noda has occurred primarily at the diploid level, n = IS , although A. crenatijlora is tetraploid and A. cristata includes diploids, tetraploids, and hexapJoids, and 3) that A. thurberi and Periptera form a lineage based on n = 13, which probably was derived from Anoda sect. Liberanoda or its progenitors.