579 
Austrostipa, a new genus, and new names 
for Australasian species formerly included 
in Stipa (Gramineae) 
S.W.L. Jacobs and J. Everett 
Abstract 
Jacobs, S.W.L., and Everett, J. (Royal Botanic Gardens, Sydney, Australia, 2000) 1996. Austrostipa, a neiv 
genus, and new names for species in Australasia fonnerly included in Stipa (Gramineae). Telopea 6(4): 
579-595. The genus Austrostipa is described to include all of the native Australian species formerly 
included in Stipa, all relevant new combinations are provided, and a new species, Austrostipa 
geoffreyi, is described. Austrostipa is divided into 13 subgenera. Tlie generic placements of the 
species introduced to Australia in either Nassella or Achnatherum are confirmed, new combinations 
are provided for the New Zealand Achnatherum petriei and the introduced Achnatherum 
caudatum, and the genus Ancmanthele is retained. Keys are provided to genera of the Stipeae and 
to the subgenera of Austrostipa. 
Introduction 
The tribe Stipeae has been defined in several ways (Clifford & Watson 1977, Clayton 
& Renvoize 1986) relying on anatomical, micromorphological and floral characters. 
The shared derived character that so far best defines the tribe is the Stipoid embryo, 
a modified Pooid embryo that is small relative to the endosperm, has (i) the scutellum 
and embryonic leaf traces diverging from the same point with no internode, (ii) an 
epiblast, (iii) the scutellum and coleorrhiza fused, (iv) the embryonic leaf margins 
not overlapping, and (v) the primary root bent at a sharp angle from the main axis 
of the embryo (Reeder 1957). Correlated with this, but not exclusive to the Stipeae, 
are single-flowered spikelets, disarticulation above the glumes, and absence of a 
rhachilla extension. Current work on rDNA (ITS) in the Stipeae is confirming that 
the tribe is monophyletic (Hsiao et al. 1995, Hsiao pers. comm.). 
We (Vickery et al. 1986, Jacobs et al. 1989) suggested that 61 endemic Australian, one 
endemic New Zealand and five introduced species were congeneric with Stipa L. but 
that a broader study would be needed to clarify the relationships. To date we recognise 
one species of Ancmanthele endemic to New Zealand, one introduced species of 
Nassella (N. trichotoma) and one introduced species of Piptatherurn (P. niiliaceum) (Jacobs 
& Everett 1993). 
Since our statements on the generic relationships Barkworth & Everett (1987), Everett 
(1990) and Barkworth (1990, 1993) have presented results from cladistic analyses of 
the species and genera of the tribe. Hsiao (pers. comm.) and Hsiao et al. (1995) have 
also been analysing nuclear rDNA (ITS) sequences. As a result of the earlier studies 
Barkworth (1990) made 68 new combinations in Nassella, and (Barkworth 1993) 36 
new combinations and one new species in Achnatherum, and five new combinations 
in Hesperostipa. Barkworth (1993) recognised nine genera in the 'core' or traditional 
part of the tribe Stipeae, Achnatherum, Piptatherurn, Oryzopsis, Ptilagrostis, Piptochaetium, 
Nassella, Hesperostipa, Stipa and Ancmanthele. She also acknowledged that the 
Australian species may not fit into any of these genera. 
