Tetrarrhena juncea

Tetrarrhena juncea R. Br. Prodr. 210(1810).

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

Type of Basionym or Protologue Information: Australia, Lewin to Wilson promontories:  Brown 6168 (K iso).

Key references (books and floras): [1810]. R.Brown, Prodromus (210), [1878] G.Bentham, Flora Australiensis 7 (554), [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), [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South Wales (381), [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  (61, fig. 26), [1984] N.T.Burbidge. rev. S.W.L.Jacobs, Australian Grasses  (253), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn (381), [2009]. A.Wilson (ed.), Flora of Australia 44A: Poaceae 2 (378, Fig. 51).

Habit. Perennial. Stolons present. Culms decumbent or sprawling, 50–400 cm tall, wiry. Mid-culm internodes glabrous. Leaf-sheath auricles absent. Ligule an eciliate membrane or a fringed membrane, a ciliolate membrane or a ciliate membrane, 0.1–0.2 mm long, membranous. Leaf-blades flat or involute, 1–13 cm long, 1–7 mm wide. Leaf-blade surface scabrous.

Inflorescence. Inflorescence solid, a raceme. Racemes 1, 2–5 cm long.

Spikelets. Spikelets sessile or pedicelled. Fertile spikelets 1-flowered, comprising 2 basal sterile florets, comprising 1 fertile floret(s), without rachilla extension, oblong, laterally compressed, 3–6 mm long.

Glumes. Glumes dissimilar, thinner than fertile lemma. Lower glume ovate, membranous, without keels or keeled, 3–5 -nerved. Upper glume ovate, 2–3.3 mm long, membranous, without keels, 5–7 -nerved. Florets. Basal sterile florets 2 or more, barren, without significant palea. Lemma of lower sterile floret 100 % of length of spikelet, coriaceous, 1-keeled, 7 -nerved, muticous. Lemma of upper sterile floret 4–5.4 mm long, muticous.

Fertile lemma 3.8–5.2 mm long, keeled, 7 -nerved. Lemma surface glabrous. Palea 1 -nerved, 1-keeled. Lodicules present. Anthers 4.

Continental Distribution: Australasia.

Australian Distribution: South Australia, Queensland, New South Wales, Victoria, Tasmania.

South Australia: Southern Lofty. Queensland: Moreton. New South Wales: North Coast, Central Coast, South Coast, Northern Tablelands, Central Tablelands, Southern Tablelands. Victoria: East Gippsland, Eastern Highlands, Gippsland Highlands, Gippsland Plain, Grampians, Midlands, Otway Plain, Otway Range, Wilsons Promontory, Wannon. Tasmania: North West, West Coast.

Notes. Usually climbing over other vegetation in eucalyt forests. Flowers Oct.-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