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Telopea Vol. 6(4): 1996 
species of Chionochloa on the Australian mainland and another on Lord Howe Island 
(Jacobs 1988), and their affinities to the rest of the genus have recently been analysed 
(Linder in prep.). However, there have been disputes about the correct names for the 
'new' genera. Veldkamp (1980) proposed the conservation of Notodanthonia over 
Rytidosperma, and to change the typification of Plinihanthesis, replacing it with the 
new name Blakeochloa, but Iris arguments were opposed by Jacobs (1982), and the 
proposal was rejected. The delimitation of the new genera is still controversial, with 
Clayton and Renvoize (1986) proposing a wider concept of Rytidosperma, including 
Erythranthcra, Karroochloa and Merxmiiellera. Further, there are controversies about 
the recognition of some of the segregate genera, in particular Rytidosperma, in Australia 
(Conert 1975, 1987, Jacobs 1982). Despite the acceptance of Rytidosperma as a distinct 
genus in New Zealand and South America, it has not been generally accepted in 
Australia where Danthonia has been preferred (Jacobs 1982,1994, Simon 1993, Beadle 
et al. 1982, Stanley & Ross 1989, Walsh 1995, but see Blake 1972). 
The danthonioid grasses are economically important in Australia as a high-quality 
native fodder (Whalley 1991, Mitchell 1991, Robards et al. 1967, Wilson & Leigh 1970), 
particularly due to their drought resistance, their ever-green habit — they retain green, 
digestible leaves even in the dry seasons (Leigh 1991) — and their good response to 
grazing. In addition, danthonioids are common to dominant elements in the temperate 
grasslands of New South Wales, Victoria and Tasmania (Scott & Whalley 1982, Lodge 
& Whalley 1989). This has led to extensive ecological and biological research into the 
group, directed at understanding the dynamics of grasslands in paddocks (Scott & 
Whalley 1984, Lodge & Whalley 1989) and at the domestication of the more suitable 
species (Lodge & Groves 1991). Consequently a stable taxonomy is of some importance. 
Generic delimitations in a widespread austral group like the danthonioid grasses 
cannot be done in continental isolation in Australia, and there have been two recent 
attempts at addressing the problem globally. Jacobs (1982) critically reviewed the 
evidence for segregating the genera, and Tomlinson (1985) surveyed the danthonioid 
grasses for anatomical and lodicule characters. However, neither of these two excellent 
studies presented comprehensive reviews of the available data, a task which would be 
necessary for the best evaluation of the evidence. 
There is some doubt about the monophyly of the Arundinoideae. Phenetic 
morphological studies (Hilu & Wright 1982) and an analysis of prolamin variation 
(Hilu & Esen 1990) produced results consistent with a monophyletic Arundinoideae, 
although the sampling for the latter study was insufficient to test the hypothesis 
rigorously. Ellis (1987) failed to find leaf anatomical support for a monophyletic 
Arundinoideae, while the cladistic analyses of morphological data conducted by 
Kellogg and Campbell (1987) could not retrieve the Arundinoideae. A parsimony 
analysis of rhcL sequence data demonstrated the polyphyly of the Arundinoideae 
(Barker et al. 1995). Until such time as a monophyletic subfamily classification is 
available, there appears to be little sense in using the subfamily classification, at 
least for the Arundinoideae. However, a large group of genera of the Arundinoideae 
are clearly related. Hilu and Esen (1990) showed that Danthonia s.l. and Cortaderia 
have very similar prolamins, and that these are rather different from the prolamins 
of the next most similar genus, Phragmites, as well as the rest of the grasses. This 
relationship was further demonstrated by both rbcL (Barker et al. 1995) and rpoC. 
(Barker 1995) analyses, and in addition there are several morphological characters 
which define this clade; haustorial synergids (Philipson & Connor 1984, Verboom et 
al. 1994), bilobed prophylls and ovaries with distant styles. There is as yet no formal 
taxonomy for this group, but as it is to some extent congruent with the tribe 
Danthonieae, as delimited by Watson and Dallwitz (1992), we refer to it in the rest 
of the paper as the 'danthonioid grasses'. 
