Deschampsia

Deschampsia* Ess. Agrostogr. 91 (1812).

Derivation:. After Dr. Deschamps of Saint-Omer.

Key references (keys and floras):. G.Bentham, Flora Australiensis 7: 587 (1878); E.E.Henty, Manual Grasses New Guinea 63 (1969); J.P.Jessop, Flora of South Australia 4: 1911 (1986); B.K.Simon, Key to Australian Grasses 95 (1993); S.W.L.Jacobs and S.M.Hastings, Flora of New South Wales 4: 593 (1993); N.G.Walsh, Flora Victoria 2: 456 (1994); D.I.Morris, Student's Flora of Tasmania 4B: 242–243 (1994); E.Edgar and H.E.Connor, Flora of New Zealand 5: 307–314 (2000); D.Sharp and B.K.Simon, AusGrass (2002); J.P.Jessop, Grasses of South Australia 209–211 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th Ed, 195–196 (2008); A.Wilson (ed.), Flora of Australia 44A: Poaceae 2: 256–258 (2009).

W.D.Clayton & S.A.Renvoize, Genera Graminum (1986), genus (187).

Naturalised. 40 species, from North and South temperate regions, high altitude tropics. 2 species in Australia, SA, NSW, Vic, and Tas. Also New Guinea, Malesia and New Zealand.

Habit. Perennial (in Australia), rhizomatous or stoloniferous or tufted or decumbent (but usually tufted). Leaf blades narrow. Ligule an unfringed membrane.

Inflorescence. Inflorescence paniculate, usually open.

Spikelets. Spikelets laterally compressed, pedicelled; with naked rachilla extension (the terminal extension well developed). Fertile spikelets laterally compressed, disarticulating above glumes.

Glumes. Glumes unequal (rarely) or more or less equal, shorter than spikelet to exceeding florets, long relative to adjacent lemmas, pointed, awnless, keeled or non-keeled, similar (subscarious to membranous, with thin margins). Lower glume 1 nerved or 3 nerved. Upper glume 3 nerved or 5 nerved.

Florets. Fertile florets 2(–3). Lemmas similar in texture to glumes to decidedly firmer than glumes (hyaline to cartilaginous), entire at apex or incised (2-lobed, 4-toothed or truncate), awned (usually) or muticous to mucronate, 5–7 nerved, not keeled (rounded on the back). Awns 1, dorsal, slender, weakly geniculate or non-geniculate, hairless (glabrous to scabridulous), much shorter than body of lemma to much longer than body of lemma. Palea relatively long, tightly clasped by lemma, 2 nerved, 2 keeled. Distal incomplete florets when present, 1. Callus short, blunt. Lodicules 2. Stamens 3. Stigmas 2. Grain small, longitudinally grooved, compressed dorsiventrally or terete. Hilum short. Embryo large (rarely) or small. Endosperm hard.

Kranz Anatomy. C3.

2n = 14, 24, 26, 32, 42, 52, and 56, 2, 4, 6, and 8 ploid, commonly adventive.

Habitat. Helophytic, mesophytic. Meadows, upland grasslands and woods. Shade species and species of open habitats.

Classification. Pooideae; Poeae.

Notes. A tolerably uniform genus sharing some of its characters with a number of other genera. It may be distinguished from Helictotrichon (incl. Amphibromus) by its small delicate spikelets and slender awns; and from Trisetum by its rounded lemma back or, less reliably, by the lemma tip and awn insertion (Clayton and Renvoize, 1986).

Types Species. D. caespitosa P.Beauv.

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