Eleusine

Eleusine* Fruct. 1: 7 (1788).

Derivation:. From Eleusis, the Greek town where the corn goddess Demeter was worshipped.

Key references (keys and floras):. G.Bentham, Flora Australiensis 7: 614–616 (1878); C.A.Gardner, Flora of Western Australia 1 Gramineae 207–208 (1952); E.E.Henty, Manual Grasses New Guinea 88 (1969); M.Lazarides, Tropical Grasses S.E.Asia 171–172 (1980); M.Lazarides, Flora of Central Australia 462 (1981); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 214–215 (1983); J.P.Jessop, Flora of South Australia 4: 1933–1934 (1986); M.Lazarides, F.Quinn and J.Palmer, Flora of the Kimberley Region 1156–1157 (1992); B.K.Simon, Key to Australian Grasses 108 (1993); S.W.L.Jacobs and S.M.Hastings, Flora of New South Wales 4: 528–529 (1993); N.G.Walsh, Flora of Victoria 2: 569 (1994); E.Edgar and H.E.Connor, Flora of New Zealand 5: 522–524 (2000); D.Sharp and B.K.Simon, AusGrass (2002); K.Mallet (ed.), Flora of Australia 44B: Poaceae 3: 416–418 (2005); J.P.Jessop, Grasses of South Australia 355–357 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th Ed, 235 (2008).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (370).

Naturalised. 9 species, from tropical and subtropical regions. 3 species in Australia, WA, NT, SA, Qld, NSW, and Vic. Also New Guinea and Malesia.

Habit. Annual or perennial (the culms flattened), tufted (or mat-forming). Leaf blades narrow. Ligule a fringed membrane.

Inflorescence. Inflorescence of spicate main branches, of digitate or subdigitate racemes or spikes, open or contracted (sometimes forming a capitulum), digitate or subdigitate (then shortly racemose, but clustered at the top of the culm).

Spikelets. Spikelets laterally compressed, more than 2 flowered, with 2 or more fertile florets, solitary, sessile to subsessile; with naked rachilla extension. Fertile spikelets adaxial (with lower glume against rachis), disarticulating above glumes or not disarticulating (E. coracana).

Glumes. Glumes unequal, shorter than spikelet, shorter than adjacent lemmas, awnless, keeled, with keel conspicuously winged or without a median keel-wing. Lower glume 1 nerved. Upper glume 3–5(–7) nerved.

Florets. Fertile florets 3–15. Lemmas not becoming indurated, entire at apex, pointed or blunt, muticous to mucronate, 3 nerved, glabrous, 1 keeled. Palea apically notched, 2 nerved. Palea keels winged or wingless. Lodicules 2. Stamens 3. Grain small, ellipsoid to subglobose, longitudinally grooved or not grooved, globose or trigonous, sculptured. Hilum short. Pericarp thin (hyaline). Embryo large.

Kranz Anatomy. C4, biochemical type NAD-ME (2 species).

2n = 18, 20, 36, and 40, 2 and 4 ploid, commonly adventive.

Habitat. Mesophytic, xerophytic. Savanna, grassland, weedy places. Species of open habitats.

Classification. Chloridoideae; Cynodonteae.

Notes. Active speciation in East Africa has made this a taxonomically difficult genus. It is linked to Acrachne, and then by further sterilisation of the rachis tip, to Dactyloctenium (Clayton & Renvoize, 1986).

Types Species. E. coracana (L.) Gaertn.

Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.

AVH 2011

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith