From Botanical Knowledge
A broad circumscription of Microseris, including Apargidium and excluding Nothocalaïs,
has usually been accepted (e.g., K. L. Chambers 1955, 1960). Recently, molecular data have led to reinstatement of the monotypic genus Uropappus and separation of two other species as the allotetraploid genus Stebbinsoseris (R. K. Jansen et al. 1991b; Chambers 1993c). A large body of literature has resulted from use of Microseris as a model genetic system by K. Bachmann and colleagues (e.g., Bachmann et al. 1979; Bachmann 1992; Bachmann and J. Battjes 1994). Differences in the diploid DNA amount within and between species have been studied by H. J. Price and colleagues (Price and Bachmann 1975; Price et al. 1981, 1983). Additional genetic studies, not referenced here, have involved three species from Australia, New Zealand, and Chile, widely disjunct from the main center of distribution in western North America. Ten of the species are diploid (2n = 18); the four tetraploid species (2n = 36) are of alloploid origin. The nine North American perennial taxa are closely related and mostly allopatric, occupying different habitats or climatic zones. The five annual species, which sometimes occur in sympatric clusters, are difficult to distinguish without the presence of cypselae.
Facts about "MICROSERIS"