Derivation
Nassella (Trin.) Desv., in C.Gay, Fl. Chil. 6: 263 (1854); from the Latin diminutive of nassa (a narrow-necked wicker basket), referring to the shape of the floret of some South American species.

hyalina-from the Greek hyalos (glass) and -ina (belonging to).

Published in
Taxon 39: 610 (1990).

Habit
Perennial, tufted. Culms erect or geniculately ascending, 25–120 cm tall. Lateral branches simple or sparsely branched. Leaf-sheaths smooth, glabrous on surface. Ligule an eciliate membrane, 0.2–2 mm long, membranous, truncate or obtuse. Collar glabrous or pubescent. Leaf-blades flat or involute or convolute, 4–30 cm long, 1.5–5.5 mm wide. Leaf-blade surface scabrous. Leaf-blade apex acute.

Inflorescence
Inflorescence compound, a panicle, exserted. Panicle open or contracted, equilateral or nodding, 5–30 cm long.

Spikelets
Spikelets solitary. Fertile spikelets 1-flowered, comprising 1 fertile floret, without rhachilla extension, lanceolate, terete, 5.5–11.5 mm long, breaking up at maturity. Spikelets disarticulating below each fertile floret. Floret callus evident, 0.4–0.9 mm long, pubescent, obtuse.

Glumes
Glumes persistent, similar, thinner than fertile lemma. Lower glume lanceolate, 5.5–11.5 mm long, equalling upper glume, hyaline, 1–3-nerved. Lower glume lateral nerves absent or distinct. Lower glume surface smooth or asperulous. Lower glume apex acute or acuminate or attenuate. Upper glume lanceolate, 5.5–11.5 mm long, 150–200% of length of adjacent fertile lemma, hyaline, 1–3-nerved. Upper glume lateral nerves absent or distinct. Upper glume surface smooth or asperulous. Upper glume apex acute or acuminate or attenuate.

Florets
Fertile lemma linear, subterete, 3–5.5 mm long, coriaceous, 5-nerved. Lemma midnerve ciliate, hairy below. Lemma surface scaberulous, glabrous. Lemma margins convolute, covering most of palea. Lemma apex entire, with a membranous corona and sometimes surmounted by a distinct coma of hairs (on membrane), with this appendage 0.4–1 mm long, 1-awned. Median (principal) awn curved or geniculate or bigeniculate, constricted at base (of corona), 20–45 mm long overall, without a column or with a straight or slightly twisted column. Column 15 mm long, scabrous, glabrous. Palea 0.8–1 mm long, 0-nerved, without keels. Lodicules 2. Anthers 3, 1.3–2.5 mm long. Anther tip penicillate. Stigmas 2. Ovary glabrous. Grain with adherent pericarp, fusiform, 1.8–2.3 mm long, dark brown. Hilum linear, 90% of length of caryopsis.

Continental Distribution:
Australasia, South America.

Australian Distribution:
New South Wales, Victoria.

New South Wales: Central Coast, Northern Tablelands, North-Western Slopes. Victoria: Victorian Volcanic Plain.

Classification. (GPWG 2001):
Pooideae: Stipeae

Notes
An introduction from South America, uncommon on North Western Slopes of New South Wales, and common in the outer northern and western suburbs of Melbourne, Victoria.