Derivation
Lophatherum Brongn., in L.I.Duperrey, Voy. Monde, Bot., Phan. 2: 49, t. 8 (1831); from the Greek lophos (a crest, or tuft of hairs) and ather (ear of wheat, spike), referring to tufts of awns on sterile lemmas.

gracile- Latin for slender. Culms or inflorescences slender.

Published in
Voy. Monde, Bot., Phan. 2: 50 (1831).

Habit
Perennial, tufted. Roots bearing tubers. Culms 45–100 cm tall. Ligule an eciliate membrane. Leaf-blade base with a false petiole. Leaf-blades lanceolate, flat, 8–20 cm long, 14–50 mm wide. Leaf-blade venation with distinct cross nerves.

Inflorescence
Inflorescence compound, a panicle of racemes. Racemes unilateral, 3–25 cm long. Central inflorescence axis 5–30 cm long. Rhachis angular, puberulous on surface. Spikelet packing approximate or lax.

Spikelets
Spikelets solitary. Fertile spikelets many flowered, comprising 1 fertile floret, with diminished florets at the apex, lanceolate, laterally compressed, 5.6–9 mm long, falling entire.

Glumes
Glumes 2, similar to each other and to fertile lemma in texture. Lower glume oblong, 2.7–4 mm long, 75% length of upper glume, herbaceous, 1-keeled, 5-nerved, midnerve scaberulous. Lower glume surface glabrous or pilose or hirsute, hairy above or below. Lower glume apex obtuse, muticous. Upper glume oblong, 4.4–5.5 mm long, 80% of length of adjacent fertile lemma, herbaceous, 1-keeled, 5-nerved. Upper glume surface glabrous or pilose, hairy above. Upper glume apex obtuse.

Florets
Fertile lemma oblong, 5.3–6.5 mm long, herbaceous, 7–13-nerved. Lemma apex acute, 1-awned. Median (principal) awn 1–1.5 mm long overall, limb retrorsely scabrous. Palea oblanceolate, 2-nerved. Palea keels winged. Palea apex dentate. Apical sterile florets 6–12 in number. Apical sterile florets barren, in a clump, elliptic, 2.5 mm long. Apical sterile lemmas 1-awned. Apical sterile lemma awns 1.5 mm long, retrorsely scabrous. Lodicules 2, cuneate. Anthers 2, 1.5 mm long.

Continental Distribution:
Temperate Asia, Tropical Asia, Australasia, Pacific.

Australian Distribution:
Northern Territory, Queensland

Northern Territory: Darwin & Gulf, Victoria River. Queensland: Cook.

Classification. (GPWG 2001):
Centothecoideae

Notes
In northern Qld. NE Himalaya, Burma, Malaya, Sri Lanka, China, Japan, Australia. A forest grass, usually collected on the edge of swamps or in seasonally swampy sites. Flowers June, Aug.–Oct.