Tetrarrhena distichophylla

Tetrarrhena distichophylla (Labill.) R. Br. Prodr. 210 (1810).

Classification. (GPWG 2001) : Subfamily Ehrhartoideae. Tribe Ehrharteae.

Type of Basionym or Protologue Information: Tasmania: Webb (K iso).

Key references (books and floras): [1810]. R.Brown, Prodromus (210), [1878] G.Bentham, Flora Australiensis 7 (553), [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (61), [2009] A.Wilson (ed.). Flora of Australia, Vol 44A. Poaceae 2 (379).

Illustrations: [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia  (62, fig. 25).

Habit. Perennial. Stolons present. Culms decumbent, 10–40 cm tall, wiry. Mid-culm internodes pubescent or pilose or hirsute. Mid-culm nodes pubescent. Lateral branches branched. Leaf-sheath auricles absent. Ligule an eciliate membrane or a fringed membrane, a ciliolate membrane, 0.2–0.5 mm long, membranous. Leaf-blades flat or involute, 1–4.5 cm long, 1–4 mm wide. Leaf-blade surface glabrous or indumented.

Inflorescence. Inflorescence solid, a raceme. Racemes 1, 0.4–7 cm long.

Spikelets. Spikelets sessile or pedicelled. Fertile spikelets 1-flowered, comprising 2 basal sterile florets, comprising 1 fertile floret(s), without rachilla extension, elliptic, laterally compressed, 3.3–5 mm long.

Glumes. Glumes similar, thinner than fertile lemma. Lower glume ovate, membranous, without keels or keeled, 3–5 -nerved. Upper glume ovate, 1–1.7 mm long, membranous, without keels, 5 -nerved. Florets. Basal sterile florets 2 or more, barren, without significant palea. Lemma of lower sterile floret 50 % of length of spikelet, chartaceous, 1-keeled, 5 -nerved, muticous or mucronate. Lemma of upper sterile floret 3–4.7 mm long, muticous or mucronate.

Fertile lemma 2.8–4.1 mm long, keeled, 7 -nerved. Lemma surface indumented. Palea 1 -nerved. Lodicules present. Anthers 4.

Continental Distribution: Australasia.

Australian Distribution: South Australia, Victoria, Tasmania.

South Australia: South-eastern. Victoria: East Gippsland, Gippsland Plain, Grampians, Midlands, Otway Plain, Otway Range, Wilsons Promontory, Volcanic Plain, Wannon. Tasmania: King Island, North East, West Coast, Midlands, East Coast.

Notes. Variable in habitat, from swamps or damp sites to sand. Flowers Dec.-Jan.

 

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