Echinochloa macrandra P.W. Michael & J.W. Vickery. Telopea 2: 27 (1980).
Classification. (GPWG 2001) : Subfamily Panicoideae. Paniceae.
Type of Basionym or Protologue Information: Australia: Western Australia: The razorbacks, near 65 mi peg on Wyndham-Darwin road, Kimberly, swamp on heavy grey clay, annual in damp mud, seed voucher(CSIRO Acces. no. W662), 17 Apr 1956, Burbidge 5185 (HT: CANB-35478; IT: CANB-35480).
Key references (books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia.
Habit. Annual. Rhizomes absent. Stolons absent. Culms erect, 70–200 cm tall, 3–6 mm diam., 6–8 -noded. Mid-culm internodes glabrous. Mid-culm nodes glabrous. Lateral branches simple or sparsely branched. Leaf-sheaths smooth, glabrous on surface. Ligule a fringe of hairs, 1–1.5 mm long. Leaf-blades 12–40 cm long, 4–14 mm wide. Leaf-blade surface smooth or scaberulous or scabrous, glabrous.
Inflorescence. Inflorescence compound, a panicle of racemes. Racemes numerous, erect or ascending, 3–7 cm long. Central inflorescence axis 11–25 cm long.
Spikelets. Spikelets pedicelled. Fertile spikelets 2-flowered, the lower floret barren (rarely male), the upper fertile, comprising 1 basal sterile florets, comprising 1 fertile floret(s), without rachilla extension, elliptic, dorsally compressed, 4.8–6 mm long. Rhachilla internodes elongated between glumes.
Glumes. Glumes dissimilar, thinner than fertile lemma. Lower glume ovate, hyaline or membranous, without keels, 5–7 -nerved. Lower glume apex muticous or mucronate. Upper glume elliptic, 4.6–5.7 mm long, membranous, without keels, 5–7 -nerved. Upper glume surface scabrous. Upper glume apex muticous or awned. Florets. Basal sterile florets 1, male, with palea. Lemma of lower sterile floret 100 % of length of spikelet, membranous, 7 -nerved, awned.
Fertile lemma 4.5–5.3 mm long, without keel, 5 -nerved. Lemma apex mucronate. Anthers 3. Grain 3–3.1 mm long.
Continental Distribution: Australasia.
Australian Distribution: Western Australia, Northern Territory.
Western Australia: Gardner. Northern Territory: Darwin & Gulf.
Notes. More collections are needed to elucidate the range in morphological variation. It is morphologically similar to E. elliptica and E. kimberleyensis. Diagnostic feagures of E. macrandra include the slightly spreading primary branches, the well-developed palea of the lower floret and the truncate spikelet base.
Native. Restricted to the swamps near the Ord R., W.A. In tropical and subtropical sub-humid woodlands. Flowers Mar.-Apr.
