Triodia aurita M.
Lazarides. Austral. Syst. Bot.
10: 405 (1997).
Classification. (GPWG 2001) : Subfamily
Chloridoideae. Triodeae.
Type of Basionym or
Protologue Information: Northern Territory: Darwin and Gulf District; Lat
13º33' S, Long. 132º17' E, 7.xii.79., C.R. Dunlop 4214 (HT: CANB; IT:
BRI, DNA, MEL).
Key references
(books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
Australia.
Illustrations:
[2005] K.Mallet (ed.), Flora of Australia 44B: Poaceae 3 (Fig.
37A-E).
Habit.
Perennial. Leaf-sheaths smooth, glabrous on surface. Leaf-sheath auricles
present. Ligule a fringe of hairs, 1–1.3 mm long. Leaf-blades straight,
filiform, conduplicate, 12–25 cm long, 1.2 mm wide.
Inflorescence.
Inflorescence compound, a panicle. Panicle elliptic, effuse, 25 cm long.
Spikelets.
Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile
florets (7–9), comprising 7–9 fertile floret(s), with diminished florets at the
apex, lanceolate, terete, 9–13 mm long.
Glumes.
Glumes similar, thinner than fertile lemma. Lower glume elliptic or oblong,
cartilaginous, without keels or keeled, 1-keeled, 1–3 -nerved. Lower glume
surface glabrous. Lower glume apex mucronate. Upper glume elliptic or oblong,
4–5 mm long, cartilaginous, without keels or keeled, 1-keeled, 1–3 -nerved.
Upper glume surface asperulous, glabrous. Upper glume apex mucronate.
Florets.
Fertile lemma 5–6 mm long, without keel, 5 -nerved. Lemma surface indumented.
Lemma apex dentate or lobed, mucronate. Median (principal) awn from a sinus,
1.2 mm long overall. Lodicules present. Anthers 3.
Continental
Distribution: Australasia.
Australian
Distribution: Northern Territory.
Northern Territory:
Darwin & Gulf.
Notes.
Only known from two collections.
Distinguished by the lanceolate, terete,
closely flowered spikelets; mucronate overlapping glumes; small, unequal lobes
of lemma; auricled leaf sheaths; open panicle of distant long-pedicelled
spikelets; relatively broad, few-nerved glumes and lemmas. The extremely
long-haired callus is a particularly prominent character.
T. aurita shares a number of
distinctive features with T. plectrachnoides, viz. auricled leaf
sheaths, mucronate glumes, long-bearded callus and similarly lobed lemma.
However, the spikelets of the two species differ markedly in morphology,
dimensions and indumentum, and their auricles in indumentum.
Known
only from the type locality, N.T. Sandstone hills; flowers May.
