A quantitative study of morphology in Australian Craspedia (Asteraceae, Gnaphalieae)

The first comprehensive quantitative study of morphological characters in all Australian species of the billy button genus Craspedia (Asteraceae, Gnaphalieae) is presented. Homogeneity analysis and pair-wise reclassification tests are used to test species circumscriptions under the genotypic-cluster concept. Although most species are supported, C. aurantia and C. jamesii do not form separate morphological clusters, and C. jamesii is reduced to a variety of C. aurantia. Although our results indicated that C. variabilis may be synonymous with C. glauca, we reserve judgment because of the small number of specimens of the latter species included in the present study. Other species were found to be less problematic; however, additional and more detailed studies will be needed to clarify the circumscription of various species with woolly leaf indumentum, in particular C. canens, C. coolaminica and C. macrocephala. A synopsis of all Australian species of Craspedia is presented, together with a preliminary key.