Relationships and Generic Concepts within Styphelieae (Epacridaceae)

Abstract

A morphological data base of 30 characters has been assembled for 33 terminal taxa in the tribe Styphelieae sensu Powell et al. (1996), as well as four outgroup taxa representing the other major affinity groups previously identified within the Epacridaceae on morphological and molecular data. Heuristic and bootstrap analyses provided strong support for the tribe, but indicated a need to modify several long-established generic concepts. Four genera are shown here to be polyphyletic. Six new monotypic genera should be segregated from Astroloma. Brachyloma should be divided into three segregates. Two distinct affinity groups warranting generic status were identified within Cyathodes. The separation of the monotypic Western Australian genus, Croninia, from Leucopogon s.l. is supported, and four other separate entities are here recognised: four species from section Heteranthus Benth. should be united with Lissanthe, and the other three segregates warrant generic status. In addition, Monotoca is paraphyletic, and should be redefined to incorporate Oligarrhena, while a new genus, ‘Pseudactinia’, is required to accommodate two new species from Western Australia. There seems little justification for maintaining the distinction between Trochocarpa and Decatoca. The pattern of intergeneric relationships resolved suggests that Astroloma s.l., Coleanthera, Conostephium, Croninia, Melichrus, Styphelia and much of Leucopogon s.l. constitute an affinity group, and that Brachyloma s. str. and B. scortechinii are basal within the tribe, but there is only weak support for these aspects of the topology within the data.