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Telopea Vol. 6(4): 1996 
Thonandia 
The T. lougifolia clade is defined primarily by the abaxial lemma surface indumentum, 
which consists of a short, even indumentum, terminating abruptly in the long tufted 
hairs of the upper indumentum row. In addition, the lemma lobes are very long with 
short setae, and the inflorescences are lax, often linear, with pale-green spikelets. 
Three of the five species have extravaginal innovations. These grasses are generally 
found in semi-shaded habitats in open woodland, and along rain-forest margins. 
They appear to avoid open grasslands and full-sun habitats where they would get 
heavily frosted, being found along the slopes of the escarpment, but never on the 
Tablelands: in the A.C.T. they are found only on the steep slopes of the gorges, 
growing in light shade. This clade includes T. semiannularis, T. lougifolia, T. gracilis, 
T. nigricans and T. imflrede. A similar indumentum is also found in the West Australian 
N. occidentalis, but this peculiar species also shows some characters of the N. caespitosa 
clade, and will be discussed in more detail under Notodanthonia. 
This segregate has not been recognised before. Zotov (1963) established a subsection 
Semiannularia, which included N. tenuior, N. biannularis and T. semiannularis. He 
defined the group by its scattered lemma-back hairs, and the relatively short setae 
on the lemma lobes. Vickery (1956) also placed the species of this group together. 
There is therefore no formal name available for this genus, and we name it Thonandia, 
which is an anagram for Dantlwnia. 
Notodanthonia 
The Notodanthonia clade is defined primarily by the massively enlarged callus, and 
the correspondingly minute rachilla internode. In addition, the leaf blades are 
generally softly hairy. The abaxial lemma surfaces generally have two neat rows of 
tufted indumentum, but in several species there are scattered hairs between the 
rows, while in some other species the lower row is diffuse. However, the indumentum 
below the upper row never forms a short, even indumentum as in Thonandia. This is 
a large clade, that has diversified on the Australian tablelands: it includes 28 species. 
The species are virtually restricted to sunny grasslands, although some species may 
also be found in light shade in open woodland (e.g. N. poiicillata, N. carphoides). This 
is the group that has become economically important as pasture grasses, and for this 
reason several species have been introduced into New Zealand. The species are 
mostly closely related to each other, and difficult to distinguish, with many 
intermediate forms. The group contains substantial variation in the lemma 
indumentum, as well as the shape of the palea, and subgroups within it may be 
recognised on this basis. 
Two species are somewhat problematic. N. occidentalis has the massive callus typical 
of this group, but the lemma indumentum is like that of Thonandia. However, in all 
other respects the species is rather like N. acerosa, and the most likely interpretation 
of the indumentum character would be a convergence to Thonandia. N. alpicola is 
somewhat more difficult. It lacks the typically massive callus of the genus, but is 
also peculiar in several other characteristics like the thickened leaves. Its closest 
relative is probably N. caespitosa, and Vickery regarded it as an alpine variant of that 
species. The smaller callus is consequently regarded as a reversal. 
Zotov (1963) included the New Zealand species of this group in his section 
Semiannularia, together with the species of Thonandia mentioned above: however, no 
further attempt had been made to recognise this group of species. 
