Enneapogon Essai Agrost. 81, 161 (1812).
Derivation:. From Greek ennea (nine) and pogon (beard), alluding to the nine plumose lemma awns.
Taxonomic revisions, nomenclatural references:. N.T.Burbidge, Proc. Linn. Soc. Lond. Session 153: 52–91 (1941); E.K.Z.Kakudidi, M.Lazarides and J.A.Carnahan, Aust. Syst. Bot. 1: 325–353 (1988).
Key references (keys and floras):. G.Bentham, Flora Australiensis 7: 600–601 (1878) as Pappophorum; C.A.Gardner, Flora of Western Australia 1 Gramineae 28–33 (1952); E.E.Henty, Manual Grasses New Guinea 88 (1969) M.Lazarides, Flora of Central Australia 453–455 (1981); J.C.Tothill and J.B.Hacker, Grasses of Southern Queensland 220–222(1983); J.P.Jessop, E.K.Z.Kakudidi, M.Lazarides, Flora of South Australia 4: 1926–1931 (1986); M.Lazarides, F.Quinn and J.Palmer, Flora of the Kimberley Region 1158–1160 (1992); B.K.Simon, Key to Australian Grasses 109–110 (1993); S.W.L.Jacobs and S.M.Hastings, Flora of New South Wales 4: 514–517 (1993); N.G.Walsh, Flora of Victoria 2: 552–554 (1994); D.Sharp and B.K.Simon, AusGrass (2002); K.Mallet (ed.), Flora of Australia 44B: Poaceae 3: 188–202 (2005); J.P.Jessop, Grasses of South Australia 330–337 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th ed, 239–242 (2008).
W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (301).
Native. 30 species, from warm regions. 15 species in Australia, WA, NT, SA, Qld, NSW, and Vic. Also New Guinea and Malesia.
Habit. Annual (rarely) or perennial, tufted. Leaf blades narrow. Ligule a fringe of hairs. Hidden cleistogenes (when present) in leaf sheaths (often basal and very modified).
Inflorescence. Inflorescence paniculate, a spike-like panicle, feathery, contracted.
Spikelets. Spikelets laterally compressed or subterete or dorsally compressed, more than 2 flowered, with 1 fertile floret or with 2 or more fertile florets, unawned or awned, solitary, shortly pedicelled; with naked rachilla extension. Fertile spikelets disarticulating above glumes.
Glumes. Glumes unequal to more or less equal, about equal to spikelet, long relative to adjacent lemmas, hairy or hairless, awnless, similar (membranous). Lower glume 3–23 nerved. Upper glume 5–21 nerved.
Florets. Fertile florets 1–4. Lemmas decidedly firmer than glumes (firm or leathery), not becoming indurated, incised, deeply cleft (into awns), awned, 9 nerved (smooth or ribbed), villous hairy. Awns usually 9 (7–12), the median similar in form to laterals, apical, non-geniculate, hairless or hairy or long-plumose, about as long as body of lemma to much longer than body of lemma. Lateral awns about equalling median. Palea relatively long (longer than the body of the lemma), entire (pointed), 2 nerved. Palea keels hairy. Distal incomplete florets underdeveloped (sterile or rudimentary) or specialised and modified (sometimes reduced to awns and forming a brushlike appendage). Callus short. Lodicules 2. Stamens 3. Grain small, compressed dorsiventrally. Hilum short. Pericarp thick and hard. Embryo large.
Kranz Anatomy. C4, biochemical type NAD-ME (7 species).
2n = 18, 36, and 40, 2 and 4 ploid.
Habitat. Xerophytic. Bushland and semidesert. Species of open habitats.
Classification. Chloridoideae; Pappophoreae.
Notes. A very uniform genus whose species closely resemble one another. A few species have cleistogamous inflorescences in the upper leaf-sheaths which are dispersed by disarticulation at the culm nodes, or they have solitary cleistogenes in the basal sheaths (Clayton and Renvoize, 1986).
Types Species. E. desvauxii P.Beauv.
Biogeographic Element. Clifford & Simon 1981, Simon & Jacobs 1990: Gondwanan.