Common name
Canegrass

Derivation
Ophiuros Gaertn., Fruct. 3: 3 (1805); from the Greek ophis (serpent) and oura (tail), alluding to the smooth spikes with the scale-like appressed lower glumes of the spikelets.

exultatus - Latin for raised up, tall.

Published in
Rev. Gen. Pl. 2: 780 (1891).

Common synonyms
Ophiuros megaphyllus Stapf ex Haines

Habit
Perennial. Culms robust, 150–250(–400) cm tall. Lateral branches branched. Leaf-sheaths pilose, with tubercle-based hairs. Leaf-sheaths outer margin hairy. Ligule an eciliate membrane. Leaf-blades linear or elliptic, flat or convolute, 50–100 cm long, 10–40 mm wide. Leaf-blade surface glabrous or pilose. Leaf-blade margins spinulose.

Inflorescence
Inflorescences arranged within a synflorescence. Inflorescence terminal and axillary, subtended by a spatheole. Spatheole linear, 3–6 cm long. Peduncle straight or nodding, 1–7 cm long, glabrous, widened at apex. Spikes single, bilateral, 2–10 cm long, 0.6–1.4 mm wide. Spike internodes oblong, 2.5–4 mm long. Spike internode tip crateriform, transverse or oblique. Rhachis fragile at the nodes, subcylindrical and excavated. Spikelet packing abaxial, regular, 2-rowed.

Spikelets
Spikelets sunken, in pairs. Pedicels fused to internode, wholly united. Companion spikelets represented by barren pedicels. Fertile spikelets 2-flowered, comprising 1 fertile floret, lower floret male, upper fertile, without rhachilla extension, oblong or ovate, dorsally compressed, 2.5–4 mm long, 1.5 mm wide, falling entire, deciduous with accessory branch structures. Spikelet callus base truncate, with central peg, attached transversely.

Glumes
Glumes dissimilar, firmer than fertile lemma. Lower glume oblong or ovate, 100% of length of spikelet, cartilaginous or coriaceous, 2-keeled, keel-less except near apex, 5–9-nerved. Lower glume surface convex. Lower glume surface smooth or rugose or areolate, glabrous. Lower glume apex obtuse. Upper glume elliptic or ovate, hyaline or membranous, 1–3-nerved. Upper glume surface glabrous. Upper glume apex obtuse.

Florets
Basal sterile floret 1, with palea. Lemma of lower sterile floret ovate, hyaline. Fertile lemma oblong or ovate, hyaline. Palea hyaline.

Continental Distribution:
Temperate Asia, Tropical Asia, Australasia.

Australian Distribution:
Western Australia, Northern Territory, Queensland.

Western Australia: Gardner. Northern Territory: Darwin & Gulf, Victoria River. Queensland: Cook, Burke, North Kennedy, South Kennedy, Port Curtis, Leichhardt.

Classification. (GPWG 2001):
Panicoideae: Andropogoneae

Notes
Native. Occurs from India and China to tropical Australia (northern W.A., N.T. and Qld) in seasonally wet grasslands and open savannas on heavy soils. Flowers Jan.–Oct.