Linder & Verboom, Generic limits in the Rytidosperma complex 
611 
Formal taxonomy 
This is a key to the genera in the Rytidosperma complex and Notochloe, Schismus and 
Plinthanihesis, which have been adequately diagnosed in the literature, are not 
included in this key. 
1 Lemma sinus rounded; plants African . Karroochloa 
\* Lemma sinus acute, plants circum-Pacific . 2 
2 Callus 0.7-0.95 times the combined length of callus and rhachilla internode . 
. Notodanthonia 
2* Callus less than 0.7 times the combined length of callus and rhachilla internode 
. 3 
3 Abaxial lemma surface indumentum in two untidy rows, or largely with a 
glabrous, shiny back; leaves often disarticulating from the sheath 
. Rytidosperma 
3* Abaxial lemma surface with a more or less continuous felt-like indumentum, 
with at most the upper margin of this tufted; leaves not disarticulating from 
the sheath . 4 
4 Upper row of tufts absent; anthers 1.2-5.2 mm long, red . Joycea 
4* Upper row of hair tufts present; anthers 0.7-1.7 mm long, yellow to orange . 
. Thonandia 
Joycea Linder, gen. nov., Rytidosper7nati similis, sed lemmatis indumento disperse et 
caryopsidis hilo longiore magis lineareque et antheris longis rubrisque differt. 
Type: Joycea pallida (R. Br.) Linder 
Caespitose or rhizomatous grasses with intravaginal innovations and truncate, two- 
awned prophylls, plants more or less glabrous. Inflorescence an open panicle. Spikelets 
with 3-6 florets; disarticulating between the florets, callus blunt, villous, as long as 
rhachilla internode. Glumes equal, 1-7-nerved, glabrous to scaberulous along the 
veins, taller than the floret packet, acute. Lemmas 9-veined, bilobed, with the 3 
central veins fusing at the base of the geniculate awn, and the 3 lateral veins entering 
the acuminate lemma lobes; lemma indumentum of scattered long hairs covering 
the abaxial lemma surface. Awn column flat, cork-screwed, limb long and acute. 
Paleas longer than the lemma sinus, linear, truncate to bilobed, keeled, glabrous or 
villous between the keels and usually with hair-tufts on the palea margins. Lodicules 
2, rhomboid, bristly and with microhairs. Anthers 3, large, red to purple. Ovary 
stalked, glabrous; stigmas distant and separated by a small double ridge. Caryopsis 
obovate, embryo half the length of the caryopsis, hilum 20-30% of caryopsis length, 
linear to ovate. Chromosome numbers 48, 72, 96. 
This new genus is similar to Rytidosperma, but differs by the scattered lemma 
indumentum, the longer and more linear caryopsis hilum, and the long, red anthers. 
It contains three species, from South Australia, Victoria, New South Wales, Australian 
Capital Territory and Queensland. 
Joycea pallida (R. Br.) Linder, comb. nov. 
Basionym: Danthonia pallida R. Br., Prod.: 177 (1810). Aveiia brownii Spreng., 
Syst. Veg. 1: 336 (1825), non A. pallida Thunb. Notodanthonia pallida (R. Br.) Veldk., 
Taxon 29: 297 (1980). Chionochloa pallida (R. Br.) Jacobs, Taxon 31: 742 (1982). 
