Natural variation in Olearia virgata (Asteraceae)

Abstract

A recently published classification of Olearia section Divakcaster recognised four subspecies in the New Zealand endemic Olearia virgata. This revision of Olearia virgata is critically evaluated. Measurement data for leaf length and width, ray floret length, peduncle length, and the number of leaves and capitula per brachyblast were taken from herbarium specimens of each subspecies. These data were used to examine character variation in O. virgata, and to test the hypothesis that O. virgata comprises four subspecies. The dimensions obtained from the measurement data differ substantially from those given for each subspecies and the variation is continuous and with considerable overlap between the subspecies. Hierarchical cluster analyses and multivariate discriminant analysis of these six characters do not support the recognition of four subspecies. It is concluded that 0. virgata is a naturally variable species for which it is not possible to formally recognise variation.

Keywords:

• Asteraceae
• Olearia
• Olearia virgata
• subspecies
• taxonomy
• New Zealand flora