Aristida annua

Aristida annua B.K.Simon. Austrobaileya
2: 87 (1984).

Classification. (GPWG 2001) : Subfamily
Aristidoideae. Aristideae.

Type of Basionym or
Protologue Information
: Australia: Queensland: Leichardt Dist.: Gindie via
Springsure, 29 Mar 1958, P. J. Skerman s.n. (HT: BRI-11772).

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.
20A-C).

Derivation: L.
annual. Annuals.

Habit. Annual.
Culms 25–50 cm tall, 2–3 -noded. Mid-culm internodes glabrous. Lateral branches
sparsely branched or branched. Ligule a fringe of hairs, 1 mm long. Leaf-blades
straight, flat or conduplicate or involute or convolute, 7–15 cm long, 1–1.5 mm
wide. Leaf-blade surface indumented.

Inflorescence.
Inflorescence compound, a panicle. Panicle elliptic, effuse, 10–20 cm long,
5–12 cm wide.

Spikelets.
Spikelets pedicelled. Fertile spikelets 1-flowered, comprising 1 fertile
floret(s), without rachilla extension, lanceolate, terete, 7–8.5 mm long.

Glumes. Glumes
similar, thinner than fertile lemma. Lower glume lanceolate, membranous,
keeled, 1-keeled, 1 -nerved. Lower glume apex awned. Upper glume lanceolate,
7–8.5 mm long, membranous, keeled, 1-keeled, 1 -nerved. Upper glume surface
asperulous or scabrous. Upper glume apex entire, awned.

Florets.
Fertile lemma 5.5–6.5 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 10.5 mm long.

Continental
Distribution
: Australasia.

Australian
Distribution
: Queensland.

Queensland:
Leichhardt.

Notes.
A. annua is distinctive in that it is the only annual species with a
convolute lemma and an open panicle.

Restricted
to a small area of central Queensland. Black earth and basalt soils. Flowering
and fruiting March, May to June.

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