Poa infirma*
H. B. & K. F.W.H.A. von Humboldt et al., Nov. Gen. Sp. 1: 158
(1816).
Classification. (GPWG 2001) : Subfamily Pooideae.
Tribe Poeae.
Type of Basionym or
Protologue Information: IST: Humboldt Willd. hb. 1974, plate 223,
[Colombia]: Nova Granada (LE-TRIN-2638.01 (fragm., illustr.)). ST: Humboldt
& Bonpland 134, Aug 1801, Colombia (P; IST: US-1851276 (fragm. ex P),
US-2851277 (fragm. ex P-HUMB]).
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 (151), [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses
of New South Wales (352), [2009] A.Wilson (ed.). Flora of Australia,
Vol 44A. Poaceae 2 (309).
Illustrations:
[2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia (151, Fig. 104), [2008] S.W.L.Jacobs,
R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn
(352).
Habit. Annual.
Culms erect or geniculately ascending or decumbent, 1–25 cm tall, 1–3 -noded.
Lateral branches simple or sparsely branched. Leaves mostly basal. Leaf-sheaths
smooth. Ligule an eciliate membrane, 0.9–3 mm long, obtuse or acute.
Leaf-blades flat or conduplicate, (0.5–)2–5.5(–8) cm long, 0.9–4 mm wide.
Leaf-blade surface smooth, glabrous.
Inflorescence.
Inflorescence compound, a panicle. Panicle lanceolate or ovate, dense or loose,
0.5–10 cm long.
Spikelets.
Spikelets pedicelled. Fertile spikelets many flowered, with at least 2 fertile
florets (2–4), comprising 2–4 fertile floret(s), with diminished florets at the
apex, oblong or ovate, laterally compressed, 2–4 mm long.
Glumes. Glumes
similar. Lower glume ovate, membranous, keeled, 1-keeled, 1–3 -nerved. Upper
glume elliptic or oblong, 1.3–2.5 mm long, membranous, keeled, 1-keeled, 1–3
-nerved.
Florets.
Fertile lemma 1.8–2.5 mm long, keeled, 5 -nerved. Lemma surface indumented.
Lodicules present. Anthers 3.
Continental
Distribution: Europe, Africa, Temperate Asia, Tropical Asia, Australasia,
South America, and Antarctica.
Australian
Distribution: South Australia, New South Wales, Victoria, Tasmania.
South Australia:
Eyre Peninsula, South-eastern. Victoria: Gippsland Plain, Midlands,
Murray Mallee, Otway Plain, Wilsons Promontory. Tasmania: North East,
East Coast.
Notes.
Introduced. Native to Europe, now widely naturalized. Occasional but
widespread. Flowers Aug.-Nov. Fruits Sept.-Nov.
