Common name
Golden Oat Grass

Derivation
Trisetum Pers., Syn. Pl. 1: 97 (1805); from the Latin tri (three) and setum (bristle), alluding to lemmas with three awns.

flavescens- from the Latin flavesco (become yellow). Foliage yellowish.

Published in
Ess. Agrostogr. 88, 180, t. 18, fig. 1 (1812).

Habit
Perennial, tufted. Basal leaf sheaths pilose. Young shoots intravaginal. Culms erect or geniculately ascending, 20–80(–100) cm tall, 2–5-noded. Ligule an eciliate membrane, 0.3–1.1 mm long. Leaf-blades 3.5–18 cm long, 1.5–5 mm wide. Leaf-blade surface scabrous, glabrous or pubescent. Leaf-blade apex acuminate.

Inflorescence
Inflorescence solid, a panicle. Peduncle glabrous. Panicle open, elliptic, 6.5–15 cm long, 1.5–7 cm wide. Panicle branches scaberulous.

Spikelets
Spikelets solitary. Pedicels 1–4 mm long, scaberulous, puberulous. Fertile spikelets many flowered, comprising 2–4 fertile florets, with diminished florets at the apex, oblong or cuneate, laterally compressed, 5–7(–8) mm long, breaking up at maturity. Spikelets disarticulating below each fertile floret. Rhachilla internodes pubescent. Floret callus pubescent.

Glumes
Glumes persistent, dissimilar, thinner than fertile lemma, shiny, gaping. Lower glume lanceolate, 2.5–4.7 mm long, 66–75% length of upper glume, membranous, 1-keeled, 1–3-nerved, midnerve scaberulous. Lower glume lateral nerves absent. Lower glume apex acuminate. Upper glume elliptic, 4.3–6.5 mm long, equalling adjacent fertile lemma, membranous, 1-keeled, 3-nerved, midnerve scaberulous. Upper glume apex acuminate.

Florets
Fertile lemma obovate, 4.4–6.3 mm long, chartaceous, much thinner above, much thinner on margins, yellow, glossy, 5-nerved. Lemma surface asperulous, rough above. Lemma apex entire or dentate, 2-fid, 1-awned. Median (principal) awn dorsal, arising 50–66% way up back of lemma, geniculate, 5–9 mm long overall, with a twisted column. Palea gaping, hyaline. Apical sterile florets resembling fertile though underdeveloped. Anthers 3, 1.3–2.5(–2.8) mm long. Ovary glabrous. Grain with adherent pericarp, linear. Hilum punctiform.

Continental Distribution:
Europe, Africa, Temperate Asia, Tropical Asia, Australasia, North America, and South America.

Australian Distribution:
New South Wales: Northern Tablelands, Central Tablelands, Southern Tablelands.

Classification. (GPWG 2001):
Pooideae: Aveneae

Notes
Introduced. Native to Europe and the Mediterranean. Roadsides and grasslands. Flowers Nov.