Common name
Sandhill Canegrass

Derivation
Zygochloa S.T.Blake, Univ. Queensland Dept. Biol. Pap. 1: 8 (1941); from the Greek zygon (yoke, or pair) and chloa (grass), referring to dioecious spikelets.

paradoxa- from the Greek para (irregular) and doxa (opinion). Different from the expected in regard to related species.

Published in
Univ. Queensland Dept. Biol. Pap. 1 (19): 8 (1941).

Habit
Perennial, tufted. Rhizomes elongated. Culms geniculately ascending, 40–150 cm tall, 4–8 mm diam., woody. Lateral branches suffrutescent. Ligule a fringe of hairs, 0.5–1.2 mm long. Leaf-blades 1–30 cm long, 1–10 mm wide. Dioecious.

Inflorescence
Inflorescence compound, a panicle, with racemose branches, comprising 1 fertile spikelets, terminal and axillary, subtended by a spatheole, enclosed. Spatheole expanded (3 bracts), ovate (toothed), 1–2 cm long, scarious. Peduncle disarticulating. Peduncle disarticulating below uppermost sheaths.

Spikelets
Spikelets solitary. Male spikelets sessile. Fertile spikelets 2-flowered, comprising 1 fertile floret, without rhachilla extension, elliptic, dorsally compressed, acute or acuminate, 5–10 mm long, falling entire, deciduous with accessory branch structures.

Glumes
Glumes similar, thinner than fertile lemma. Lower glume ovate, 5–10 mm long, 100% of length of spikelet, chartaceous, 7–9-nerved. Lower glume surface puberulous or villous. Lower glume apex acute. Upper glume ovate, 5–10 mm long, chartaceous, 7–9-nerved. Upper glume surface glabrous or villous. Upper glume apex acute.

Florets
Basal sterile floret 1, with palea. Lemma of lower sterile floret similar to upper glume, ovate, 5–10 mm long, 100% of length of spikelet, chartaceous, 5-nerved, acute. Fertile florets female. Fertile lemma ovate, 4.5–10 mm long, indurate, of similar consistency on margins, yellow, glossy, 5-nerved. Lemma surface glabrous. Lemma margins involute. Lemma apex acute. Palea indurate. Anthers 3, 3–4.5 mm long. Grain with adherent pericarp, ovoid, 3 mm long. Male inflorescence similar to female, a spathate compound head. Male spikelets similar to female but less developed, 2-flowered, lanceolate, 5.5–8.5 mm long. Male spikelet glumes 2, 4–5.2 mm long, 7–9-nerved.

Continental Distribution:
Australasia.

Australian Distribution:
Northern Territory, South Australia, Queensland, New South Wales.

Northern Territory: Central Australia North, Central Australia South. South Australia: Lake Eyre, Gairdner-Torrens Basin, Flinders Ranges, Eastern, Eyre Peninsula. Queensland: Leichhardt, Gregory North, Gregory South. New South Wales: North Far Western Plains, South Far Western Plains.

Classification. (GPWG 2001):
Panicoideae: Paniceae

Notes
In shrub steppe shrublands, arid tussock grasslands, and arid hummock grasslands. Flowers mostly Mar.–Sept. Disarticulation is primarily at the compacted culm nodes and secondarily at the spikelet base. The disseminule consists of a spikelet, a very short pedicel, and 3 highly modified bracts with pronounced curved wings. These unusual modifications undoubtedly assist in dispersal.
Spikelets of the male inflorescence occur in a reduced panicle and the prolonged rachis, bract and prophyllum are not modified into winged structures.