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Nuytsia Vol.7, No.2 (1990) 
Key to Fimbristylis in Australia 
A draft key to all the Australian species of Fimbristylis has been prepared and is now presented. 
Twelve taxa of uncertain affinities arc included in the key. Several of these may be better 
placed in Actinoschoenus Benth. or Trachystylis S.T. Blake (or even a new genus) but arc placed in 
Fimbristylis for convenience, at this stage. Further collections and research arc required to clarify 
the situation. 
I have excluded Fimbristylis rhyticarya F. Muell. in the key as I agree with Kern (1974) dial it 
should be relegated to synonymy under F. acuminata Vahl. 
la. Glumes spirally arranged 2 
b. Glumes (at least in young spikelets) distichous; sometimes becoming twisted 
with age. Spikelets strongly laterally compressed, similar to those in Cyperus 1 14 
2a. Nut sub-cylindrical, oblong-linear in outline 3 
b. Nut not oblong-linear in outline 4 
3a. Inflorescence a single terminal spikelet, glumes obtuse, 3-5 mm long F. tetragona 
b. Inflorescence compound, glumes mucronatc, 1-2 mm long F. dipsacea 
4a. Stigmas 3, nut trigonous or triquetrous 5 
b. Stigmas 2, nut biconvex 82 
5a. Spikelets solitary on the stem 6 
b. Spikelets more than one on each stem 28 
6a. Nut winged 7 
b. Nut not winged (sometimes with an apical ridge) 8 
7a. Wing rounded, glumes obovate F pterygosperma 
b. Wing divided, glumes lanceolate 3. F. caloptera 
8a. Nut with transverse wavy ridges (sometimes obscure in F. punctata) 9 
b. Nut smooth or tuberculate, wavy ridges absent, or restricted to lower third of nut 1 1 
9a. Spikelets 1-2 flowered, nut 2.5-3 mm long F. sp. A 
b. Spikelets many flowered, nut less than 2.5 mm long 10 
10a. Style glabrous 1 mm long, glumes glabrous, 2. 5-3. 5 mm long F. ammobia 
b. Style hairy 2 mm long or more, glumes softly hairy above, 5-6 mm long .... F. punctata 
1 la. Spikelets oblique or at right angles to the stem 12 
b. Spikelets exactly terminal (except F. trigastrocarya where the spikelet 
is sometimes pushed to one side by the involucral bract) 14 
12a. Glume with two terminal wings, glabrous F. costiglumis 
b. Glume apices rounded, with ciliate margins 13 
