Triodia uniaristata

Triodia uniaristata (Lazarides) M. Lazarides. Austral. Syst. Bot. 10: 482 (1997).

Classification. (GPWG 2001) : Subfamily Chloridoideae. Triodeae.

Basionym and/or
Replacement Name:
 Plectrachne
uniaristata
Lazarides, Nuytsia 5(2): 280 (1984) [1985].

Type of Basionym or
Protologue Information
: IT: Lazarides 7764, 17 Feb 1973, Australia
(L, MO-3820764). IT: M. Lazarides 7764, 17 Feb 1973, Australia: Northern
Territory: ca. 28 mi SE of Oenpelli Mission (US-3260706).

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
34A-C).

Habit.
Perennial. Culms erect, 30–120 cm tall, 4 -noded. Lateral branches branched.
Leaf-sheaths scaberulous. Leaf-sheath auricles present. Ligule a fringe of
hairs, 1 mm long. Leaf-blades filiform, conduplicate, 20–40 cm long, 1–2 mm
wide. Leaf-blade surface scabrous.

Inflorescence.
Inflorescence compound, a panicle. Panicle linear, 15–30 cm long, 2–5 cm wide.

Spikelets.
Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile
florets (4), comprising 4 fertile floret(s), with diminished florets at the
apex, lanceolate, laterally compressed, 4.5–5.5 mm long.

Glumes. Glumes
similar. Lower glume lanceolate, membranous or cartilaginous, without keels,
3–5 -nerved. Lower glume apex awned. Upper glume lanceolate, 4.5–6 mm long,
membranous or cartilaginous, without keels, 3–5 -nerved. Upper glume surface
asperulous. Upper glume apex lobed, awned.

Florets.
Fertile lemma 4–5.5 mm long, without keel, 3 -nerved. Lemma surface indumented.
Lemma apex lobed, awned, 1 -awned. Median (principal) awn from a sinus, 13 mm
long overall. Lateral lemma awns absent. Palea 2 -nerved. Lodicules present.
Anthers 3.

Continental
Distribution
: Australasia.

Australian
Distribution
: Northern Territory.

Northern Territory:
Darwin & Gulf.

Notes.
Like P. contorta this species is unique within the genus by virtue of
its 2-lobed, 1-awned lemmas. From P. contorta, P. uniaristata is
distinguished by its smaller, fewer-flowered spikelet in which the florets are
inserted within the glumes, by its glabrous (not partly hirsute) palea, and by
its larger panicle.

Kakadu
Natl Park, N.T. Dominant on bank of small creek in sandstone gorge; sandstone
escarpment; flowers Feb.-March.


AVH 2011

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith