BAYER, RANDALL J.* and EDWARD W. CROSS. CSIRO, Division of Plant Industry, Australian National Herbarium, Canberra, ACT, 2601, Australia. - The tribal placement of several enigmatic genera of Australian Asteraceae based on molecular and morphological data.
Several genera of Australian sunflowers have been doubtfully placed in
various tribes throughout their taxonomic history. Our continuing
studies of relationships within the Gnaphalieae have led us to
investigate the tribal placement of three genera of enigmatic annual
herbs. Therefore, the objective of this study was to elucidate tribal
relationships of the genera, Haegiela P. S. Short and Paul G.
Wilson, Chondropyxis D. A. Cooke, and Elachanthus F.
Muell. by reconstructing their phylogeny within the subfamily
Asteroideae This has been accomplished through the use of sequence
data from the trnL intron, trnL/trnF intergenic spacer
and matK coding region. Haegiela tatei (F. Muell.) P. S.
Short and Paul G. Wilson was originally included in Epaltes
Cass., which has been placed in the Plucheeae. However, recent
treatments have incorporated Haegiela in Gnaphalieae.
Chondropyxis halophila D. A. Cooke is a recently described
species that has been included in both the Anthemideae and
Gnaphalieae, with a suggestion of an affinity with Astereae. The
ditypic genus Elachanthus has been placed within the genus
Cotula L., as Cotula sect. Elachanthus (F.
Muell.) Baill. (Anthemideae) and more recently in Astereae. Molecular
data does not support the traditional placements of the three genera,
but instead there is general agreement between the tribal placement of
these genera based on our molecular analysis and certain
morphological, anatomical, and secondary chemical characters.
Key words: Asteraceae, Astereae, Chondropyxis, Elachanthus, Gnaphalieae, Haegiela