Rytidosperma bipartitum

Rytidosperma bipartitum (Link) A.M. Humphreys & H.P. Linder. Ann. Mo. Bot. Gard. .

Classification. (GPWG 2001) : Subfamily Danthonioideae. Tribe Danthonieae.

Basionym and/or Replacement Name:  Avena bipartita Link, Hortus Regius Botanicus Berolinensis 1: 113. 1827.

Type of Basionym or Protologue Information: T: (B).

Recent synonyms: Notodanthonia bipartita (Link) Veldkamp, Notodanthonia bipartita (Link) Veldkamp var. linkii, Rytidosperma linkii (Kunth) Connor & Edgar var. linkii, Danthonia linkii Kunth, Austrodanthonia bipartita (Link) H.P. Linder.

Key references (books and floras): [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae, [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses of New South Wales (142).

Illustrations: [1984] N.T.Burbidge. rev. S.W.L.Jacobs, Australian Grasses  (103 as D. linkii), [2008] S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn (142).

Derivation: L. bis (twice) and partia (divide). Lemma apex bifid.

Habit. Perennial. Culms erect, 15–80 cm tall, 1 mm diam., 4 -noded. Leaf-sheaths smooth. Ligule a fringe of hairs. Leaf-blades flat or involute, 20–30 cm long, 1–2.5 mm wide. Leaf-blade surface glabrous or indumented.

Inflorescence. Inflorescence solid, a panicle. Panicle lanceolate or ovate, 4–12 cm long.

Spikelets. Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile florets (4–7), comprising 4–7 fertile floret(s), with diminished florets at the apex, cuneate, laterally compressed, 9–15 mm long.

Glumes. Glumes similar, thinner than fertile lemma. Lower glume elliptic, membranous, without keels, 5–7 -nerved. Upper glume elliptic, 8–13 mm long, membranous, without keels, 5–7 -nerved.

Florets. Fertile lemma 2.2–3.3 mm long, without keel, 9 -nerved. Lemma surface indumented. Lemma apex lobed, awned, 3 -awned. Median (principal) awn from a sinus, 7–11 mm long overall, with a twisted column. Lateral lemma awns present. Lodicules present. Anthers 3. Grain 1.4–1.7 mm long.

Continental Distribution: Australasia.

Australian Distribution: Queensland, New South Wales, Victoria.

Queensland: Burnett, Darling Downs, Maranoa, Moreton, Warrego. New South Wales: North Coast, Central Coast, South Coast, Northern Tablelands, Central Tablelands, Southern Tablelands, North-Western Slopes, Central-Western Slopes, South-Western Slopes, North-Western Plains, South-Western Plains. Victoria: East Gippsland, Gippsland Plain, Grampians, Midlands, Murray Mallee, Riverina, Volcanic Plain, Wimmera.

Notes. Very close to several species: from R. richardsonii it is separated by the more slender spikelets, and linear-lanceolate inflorescence; from R. fulvum by the weakly developed basal twisting of the awn-column.

Widespread on the Tablelands of New South Wales and in Victoria, altitude 100–1200 m, common on black soils, occasionally also in other soils, usually in sunny grassland.

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