Arthragrostis brassiana

Arthragrostis brassiana B.K. Simon. Austrobaileya 9: 188 (2010).

Type of Basionym or
Protologue Information: Queensland.
Cook District: Crest of Western Scarp of Great Dividing Range, 12 miles [19 km]
E of The Lynd, 11 July 1954, S.T.Blake 19478 ( holo: BRI; iso: AD, CANB,
DNA, K, L, MO, PERTH, PRE).

Habit. Annual.
Culms 30–70 cm tall, 3–5 -noded. Ligule a fringed membrane, 0.5–0.7 mm long.
Leaf-blades 3–9 cm long, 2–4 mm wide.

Inflorescence.
Panicle elliptic, 8–35 cm long.

Spikelets.
Spikelets pedicelled. Fertile spikelets comprising 1 basal sterile florets, 1
fertile floret(s), without rachilla extension, lanceolate or ovate, dorsally
compressed, 2–5.2 mm long. Rhachilla internodes elongated below proximal
fertile floret.

Glumes. Glumes
dissimilar, thinner than fertile lemma, dull. Lower glume lanceolate or ovate,
membranous, without keels, 3–5 -nerved. Lower glume apex muticous. Upper glume
lanceolate or ovate, membranous, 1-keeled, 5–7 -nerved. Upper glume apex
muticous. Florets. Basal sterile florets 1, barren, without significant
palea. Lemma of lower sterile floret 1 % of length of spikelet, membranous,
muticous.

Fertile lemma without
keel.

Continental
Distribution: Australasia.

Australian
Distribution: Queensland.

Queensland: Cook.

Austrobaileya description

Flowering culms 30–70 cm tall, 3–5-noded. Ligule 0.5–0.7 mm long. Leaf blades flat, 3–9 cm long, 2–4 mm wide. Inflorescence 8–35 cm long. Primary branches 3–10 cm long. Pedicels distinctly angled. Spikelets 5–10 on a typical lowermost primary branch, lanceolate to ovate, 2–5.2 mm long, 0.6–1.5 mm wide. Glumes ± equal in length, glabrous; lower glume ovate to lanceolate, 3–5-nerved; upper glume lanceolate, 5–7-nerved, acute, muticous. Lower floret sterile; lemma with apex acute; palea vestigial. Upper floret: lemma yellow or brown, apically rounded, muticous; palea cartilaginous.

Notes: This species differs from A. deschampsioides by the glumes being more or less equal in length as opposed to being distinctly unequal.

Australian
Distribution: Queensland.

Both A.
brassiana and A. deschampsioides differ from A. clarksoniana by
having glabrous glumes, as opposed to glumes with tubercle-based cilia. A.
brassiana differs from A. deschampsioides by the glumes being only
slightly unequal. There are 2 varieties in Australia.

Spikelets 3.8-5.2 mm long	4a. var. brassiana
Spikelets 2-3.5 mm long	4b. var. minutiflora

AVH 2012 © ALA