A revision of Olearia section Asterotriche (Asteraceae: Asterae)

Abstract

Recent molecular work on Olearia s.l. has not supported current generic or sectional concepts, instead identifying two major lineages loosely based on distribution. Further work is required to adequately circumscribe Olearia s.s. The present study aimed to determine the monophyly of Australian stellate-haired species of Olearia. Using four molecular regions (ITS, psbA–trnH, rpl32–trnL and matK) sequenced from 27 species, Australian stellate-haired taxa were confirmed as monophyletic. Accordingly, Olearia section Asterotriche is redefined here to include only Australian species. This section is one of the few confirmed natural groups in Olearia. Section Asterotriche is closely associated with, but does not include, the type species of Olearia, O. tomentosa (J.C.Wendl.) DC. Given this close association to the type, section Asterotriche should be retained within Olearia, pending further research that would justify any future changes. This manuscript concludes with a monograph of section Asterotriche, in it six new subspecies are described and nine taxa are lectotypified.