Nassella trichotoma*

Nassella trichotoma* (Nees) Hackel ex Arech. Anales Mus. Nac. Montevideo 1: 336 (1896).

Classification. (GPWG 2001) : Subfamily Pooideae. Tribe Stipeae.

Basionym and/or Replacement Name:  Stipa trichotoma Nees, Fl. Bras. Enum. Pl. 2(1): 375 (1829).

Type of Basionym or Protologue Information: HT: F. Sellow 833, no date, Uruguay: Montevideo (B; IT: BAA-3292 (fragm. ex B), MO-2097080, US-733007 (fragm. ex B)).

Recent synonyms: Stipa trichotoma.

Key references (books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (108), [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South Wales (305), [2009] A.Wilson (ed.). Flora of Australia, Vol 44A. Poaceae 2 (64).

Illustrations: [1984] N.T.Burbidge. rev. S.W.L.Jacobs, Australian Grasses  (187), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia  (108, Fig. 70), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn (305), [2009]. A.Wilson (ed.), Flora of Australia 44A: Poaceae 2 (63, Fig 9).

Habit. Perennial. Culms 30–60 cm tall. Leaf-sheaths smooth, glabrous on surface. Ligule an eciliate membrane, 0.5–2.5 mm long, truncate or obtuse. Leaf-blades filiform, convolute, 15–45 cm long, 0.2–0.5 mm wide.

Inflorescence. Inflorescence compound, a panicle. Panicle ovate, effuse, 8–25 cm long.

Spikelets. Spikelets pedicelled. Fertile spikelets 1-flowered, comprising 1 fertile floret(s), without rachilla extension, lanceolate, terete, 4–8.5 mm long.

Glumes. Glumes similar, thinner than fertile lemma. Lower glume lanceolate, hyaline, without keels, 3 -nerved. Upper glume lanceolate, 4–8.5 mm long, hyaline, without keels, 3 -nerved. Upper glume surface scabrous.

Florets. Fertile lemma 1.5–2.5 mm long, keeled. Lemma apex awned, 1 -awned. Median (principal) awn 15–35 mm long overall, with a twisted column. Palea 0 -nerved, without keels. Anthers 3. Grain 1.2 mm long.

Continental Distribution: Europe, Africa, Australasia, and South America.

Australian Distribution: New South Wales, Victoria, Tasmania.

New South Wales: Central Coast, South Coast, Northern Tablelands, Central Tablelands, Southern Tablelands, Central-Western Slopes, South-Western Slopes. Victoria: Gippsland Plain, Midlands, Otway Plain, Volcanic Plain. Tasmania: King Island, East Coast.

Notes. Weed of pastures, unpalatable to stock.

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