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.

Origin, Diversification, and Classification of the Australasian Genus Dracophyllum (Richeeae, Ericaceae)1

“…Our findings confirm earlier molecular studies with an expanded sample of the tribe Kron et al, 2002). Additional morphological characters that unite the members of tribe Richeeae include the presence of a single bract that subtends the sepals, sheathing leaves that leave a distinct annular scar, leaf nodes that are tri-or multilacunar, and the absence of platelet waxes on the adaxial surface of the leaves (Powell et al, 1996;Crayn et al, 1998;Kron et al, 2002;Venter, 2008). Our results also suggest the current generic circumscriptions do not form monophyletic groups (Fig.…”

“…2A-H). They are characteristic shrubs of upland forests and heathlands in mainland Australia (e.g., Powell, 1992;Streiber et al, 1999), Tasmania (e.g., Rodway, 1903;Curtis, 1963;Buchanan et al, 1989), Lord Howe Island (Oliver, 1917), New Caledonia (Virot, 1975;Venter, 2004), and New Zealand (Allan, 1961;Venter, 2002) and are commonly known as dragonleaf or grass tree because of their distinctive spiky growth form.…”

“…2I-M) includes 11 species from southeastern Australia and Tasmania (Menadue & Crowden, 2000), while Sphenotoma ( Fig. 2N-P) includes six described species that are restricted to Western Australia (Powell et al, 1996Paczkowska & Chapman, 2000). Unique morphological (Powell et al, 1996) and molecular traits Kron et al, 2002) shared by these three genera indicate that they once shared a common ancestor whose descendants form a single lineage.…”

“…2N-P) includes six described species that are restricted to Western Australia (Powell et al, 1996Paczkowska & Chapman, 2000). Unique morphological (Powell et al, 1996) and molecular traits Kron et al, 2002) shared by these three genera indicate that they once shared a common ancestor whose descendants form a single lineage. While tribe Richeeae forms a well-defined monophyletic group (Powell et al, 1996;Kron et al, 2002), the phylogenetic relationships among Dracophyllum, Richea, and Sphenotoma are less clear due to the sparse sampling in previous studies.…”

“…However, recent phylogenetic studies (Powell et al, 1996;Stace et al, 1997;Kron et al, 2002) revealed that the epacrids form a well-supported monophyletic group nested within the Ericaceae. As a consequence, they have all been transferred to the family Ericaceae, and the epacrids are now recognized as a distinct subfamily, the Styphelioideae Sweet.…”