Rytidosperma setaceum


Rytidosperma setaceum (R.Br.) Connor &
Edgar. New Zealand J. Bot., 17(3): 332 (1979).

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

Basionym and/or
Replacement Name:
 Danthonia
setacea
R.Br, Prodr. 177 (1810).

Type of Basionym or
Protologue Information
: HT: Brown 6232, Australia: Western
Australia: King George's Sound (BM; IT: BRI, K, MEL).

Recent synonyms:
Rytidosperma setaceum (R.Br.) Connor & Edgar, Danthonia setacea
R.Br. var. breviseta Vickery, Notodanthonia setacea (R.Br.)
Veldkamp, Austrodanthonia setacea (R.Br.) H.P. Linder.

Key references
(books and floras):
[1810]. R.Brown, Prodromus (77 as Danthonia
setacea
), [1878] G.Bentham, Flora Australiensis 7 (595 as Danthonia
setacea
), [1952] C.A.Gardner, Flora of Western Australia 1 Gramineae
(57 as Danthonia setacea), [2002] D.Sharp & B.K.Simon, AusGrass,
Grasses of Australia
, [2002] J.Wheeler, N.Marchant & M.Lewington, Flora
of the South West (402), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses
of South Australia
(296), [2008] S.W.L.Jacobs, R.D.B.Walley &
D.J.B.Wheeler, Grasses of New South Wales (147).

Illustrations:
[2005] K.Mallet (ed.), Flora of Australia 44B: Poaceae 3 (Fig.
10, E-F), [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South
Australia
 (296, Fig. 233), [2008]
S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales,
4th edn (147).

Derivation: L. seta,
bristle; -acea, indicating resemblance. With bristle-like leaf-blades.

Habit.
Perennial. Culms erect, stature slender to delicate, 15–60 cm tall, 2–4 -noded.
Mid-culm nodes glabrous. Leaf-sheaths glabrous on surface or hairy. Ligule a
fringe of hairs, 0.5 mm long. Leaf-blades straight or curved, filiform,
involute, 5–20 cm long, 1 mm wide. Leaf-blade surface scabrous, glabrous or
indumented.

Inflorescence.
Inflorescence solid, a panicle. Panicle linear to elliptic, 3–9 cm long.

Spikelets.
Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile
florets (4–10), comprising 4–10 fertile floret(s), with diminished florets at
the apex, cuneate, laterally compressed, 7–14 mm long.

Glumes. Glumes
similar, thinner than fertile lemma. Lower glume linear or lanceolate,
membranous, without keels, 3–5 -nerved. Upper glume linear or lanceolate, 8–14
mm long, membranous, without keels, 3–5 -nerved.

Florets.
Fertile lemma 1.5–3.2 mm long, without keel, 9 -nerved. Lemma apex lobed,
awned, 3 -awned. Median (principal) awn from a sinus, 5–9 mm long overall, with
a twisted column. Lateral lemma awns present. Lodicules present. Anthers 3.
Grain 1–1.7 mm long.

Continental
Distribution
: Australasia.

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

Western Australia:
Eucla, Irwin, Drummond, Dale, Warren, Eyre, Roe, Avon, Coolgardie. South
Australia
: Nullabor, Flinders Ranges, Eastern, Eyre Peninsula, Northern
Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South-eastern.
New South Wales: Central Coast, Southern Tablelands, Central-Western
Slopes, South-Western Slopes, North-Western Plains, South-Western Plains, South
Far Western Plains. Victoria: East Gippsland, Eastern Highlands,
Gippsland Highlands, Gippsland Plain, Grampians, Lowan Mallee, Midlands, Murray
Mallee, Otway Plain, Otway Range, Wilsons Promontory, Riverina, Snowfields,
Volcanic Plain, Wannon, Wimmera. Tasmania: Furneaux Group, North West,
North East, West Coast, Central Highlands, Midlands, Ben Lomond, East Coast,
South West.

Notes. This
species approaches several other species closely: a) differs from R.
monticola
by the more compact, bushy inflorescence, and the setae longer
than the lemma lobes; b) from R. caespitosum by the smaller spikelets,
and by the much more slender lemma, and the shorter, broader palea, and the
overlapping rows of lemma hairs (but many collections cannot be placed to
either taxon with confidence).

Widespread south of 30
latitude, absent from the Nullabor Plain, altitude 0–650 m, widespread in
semi-arid parts of country, often forming grassland with A. caespitosa
and A. eriantha. Flowers Oct. to Dec.

 

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