Elionurus Mem. Mus. Hist. Nat. (Paris) 2: 69 (1815).
Derivation:. From the Greek eleuein (to roll) and oura (tail) alluding to the spike-like racemes curling strongly when old.
Key references (keys and floras):. G.Bentham, Flora Australiensis 7: 510 (1878); E.E.Henty, Manual Grasses New Guinea 88 (1969) as Elyonurus; M.Lazarides, Tropical Grasses S.E. Asia 35–36 (1980); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 216–217 (1983); B.K.Simon, Flora of the Kimberley Region 1157 (1992); B.K.Simon, Key to Australian Grasses 108 (1993); D.Sharp and B.K.Simon, AusGrass (2002); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th Ed, 235–236 (2008).
W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (626).
Native. 15 species, from tropical and subtropical regions. 1 species in Australia, WA, NT, Qld, and NSW. Also New Guinea.
Habit. Annual or perennial, tufted. Leaf blades narrow. Ligule a fringed membrane (very short) or a fringe of hairs.
Inflorescence. Inflorescence a single raceme or paniculate (of single racemes, terminal or sometimes axillary and gathered into false panicles), a spatheathe panicle, spatheate, racemes single, not in tight heads, a compound pseudo-inflorescence or not a compound pseudo-inflorescence. Spikelet-bearing axes spikelike (flexuous), with homomorphic spikelets, solitary, disarticulating at joints. Internodes disarticulating obliquely, densely long-hairy.
Spikelets. Spikelets dorsally compressed, 2 flowered, with 1 fertile floret, paired, sessile and pedicelled, in pedicelled/sessile combinations; sessile spikelet with lower incomplete floret. Fertile spikelets falling with glumes.
Glumes. Glumes relatively large, unequal to more or less equal, (the longer) long relative to adjacent lemmas, hairy or hairless, with distinct hair tufts or with distinct rows of hairs, awned (the l.g. often cuspidate to a bifid tip, with tails several mm long) or awnless, dissimilar (the lower tougher, carinate on the edges, its keels generally glandular or with tufts of hairs, the upper membranous, lanceolate, not 2-keeled) or similar (rarely, then both subulate). Lower glume two-keeled (keels not winged, but often ciliate and bordered by a dense oil streak), convex on back to flattened on back, relatively smooth or tuberculate (then with ciliate or hair-tufted tubercles on the keels), 9 nerved. Upper glume 3 nerved.
Florets. Lower incomplete floret(s) sterile. Lemmas awnless, exceeding fertile lemmas, similar in texture to fertile lemmas (hyaline), not becoming indurated. Fertile florets 1. Lemmas less firm than glumes (hyaline), not becoming indurated, entire at apex, muticous, 0 nerved. Palea present or absent, when present, very reduced, nerveless. Lodicules 2. Stamens 3. Grain small, compressed dorsiventrally. Hilum short. Embryo large. Pedicels free of rachis (resembling the internode). Pedicelled spikelets present, different from sessile spikelet, sterile, with glumes, 2 floreted.
Kranz Anatomy. C4.
2n = 10 and 20.
Habitat. Mesophytic to xerophytic. Savanna, often on dry soils. Species of open habitats.
Classification. Panicoideae; Andropogoneae.
Notes. A fairly homogeneous genus (Clayton and Renvoize, 1986).
Types Species. E. tripsacoides Willd.
Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Gondwanan.