Aristida platychaeta S.T.Blake. Proc.
Roy. Soc. Queensland
51: 174 (1940).
Classification. (GPWG 2001) : Subfamily
Aristidoideae. Aristideae.
Type of Basionym or
Protologue Information: Australia: Queensland: Maranoa District: Mitchell,
on open downs on dark greenish brown silty clay 1100 ft., 3 May 1934, S. T.
Blake 5701 (HT: BRI; IT: BRI).
Key references
(books and floras): [1981] M.Lazarides in J.Jessop (ed)., Flora of
Central Australia (451), [2002] D.Sharp & B.K.Simon, AusGrass,
Grasses of Australia, [2008] S.W.L.Jacobs, R.D.B.Walley &
D.J.B.Wheeler, Grasses of New South Wales (131).
Illustrations:
[1983] J.C.Tothill & J.B.Hacker, Grasses of Southern Queensland
(106(30)), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses
of New South Wales, 4th edn (131).
Derivation: G.
platys, broad; chaete, bristle. Awns flattened.
Habit.
Perennial. Culms 15–50 cm tall, 1–2 -noded. Mid-culm internodes glabrous.
Ligule a fringe of hairs, 1 mm long. Leaf-blades curled or flexuous, flat or
conduplicate or involute or convolute, 4–8 cm long, 1–1.5 mm wide. Leaf-blade
surface scaberulous.
Inflorescence.
Inflorescence compound, a panicle. Panicle linear, 10–23 cm long, 2–3 cm wide.
Spikelets. Spikelets
pedicelled. Fertile spikelets 1-flowered, comprising 1 fertile floret(s),
without rachilla extension, lanceolate, terete, 5–7 mm long.
Glumes. Glumes
similar, thinner than fertile lemma. Lower glume lanceolate, membranous,
keeled, 1-keeled, 1 -nerved. Upper glume lanceolate, 5–7 mm long, membranous,
keeled, 1-keeled, 1 -nerved. Upper glume apex entire, mucronate.
Florets.
Fertile lemma 5–6 mm long, without keel, 3 -nerved. Lemma apex awned, 3 -awned.
Median (principal) awn without a column. Lateral lemma awns present. Palea
without keels. Anthers 3. Grain 3 mm long.
Continental
Distribution: Australasia.
Australian
Distribution: Queensland, New South Wales.
Queensland:
Darling Downs, Maranoa, Warrego. New South Wales:
North-Western Slopes, North-Western Plains.
Notes.
A. platychaeta differs from A. nitidula and A. arida by
the lemmas being shorter and the leaf blades being flat and flexuose to curly.
Central
southern Queensland to the north-western
plains of New South Wales.
Eucalyptus and mulga (Acacia aneura) communities on loamy and
rocky areas. Flowering and fruiting December to May, August (one record),
October (one record).
