Key to the species of Poa
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- Spikelets 12–16 mm long; glumes 9–12 mm long; lemma 7–11 mm long, lemma pointed at apex; tussock-forming rhizomatous grass of coastal sand dunes
- Spikelets 2.5–13 mm long; glumes 2.5–4 mm long; lemma 1.5–5 mm long, obtuse, truncate, or emarginate, sometimes pointed (in Poa trivialis and sometimes in Poa pratensis); habit and habitat various
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Remaining items (35)
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1Spikelets 12–16 mm long; glumes 9–12 mm long; lemma 7–11 mm long, lemma pointed at apex; tussock-forming rhizomatous grass of coastal sand dunesPoa billardierei
1Spikelets 2.5–13 mm long; glumes 2.5–4 mm long; lemma 1.5–5 mm long, obtuse, truncate, or emarginate, sometimes pointed (in Poa trivialis and sometimes in Poa pratensis); habit and habitat various2
2Annuals with soft, bright green leaves; ligule conspicuous, thinly membranous; lemma with prominent, hairy nerves; web absent3
2Perennials; ligule and web various5
3Inflorescence remaining narrow, often almost spike-like; spikelets mostly more than 5-flowered; lemma 9–11-nerved; native species of dry north-west and south-west coastPoa fax
3Inflorescence finally ovate or triangular, with spreading branches; spikelets mostly 5- or fewer-flowered; lemma 5-nerved; widespread weeds4
4Spikelets mostly pedicellate; lemma more than 2.5 mm long; anthers 0.7–1.3 mm longPoa annua
4Spikelets often sessile or subsessile; lemma less than 2.5 mm long; anthers 0.2–0.5 mm longPoa infirma
5Plants bulbous at base or with distinctly bead-like lower internodes; ligule prominent, thinly membranous6
5Plants not bulbous at base, lower internodes not or barely swollen; ligule various8
6Spikelets plump, almost as broad as long, often pendent; web absent or rudimentary; panicle rather sparse, with very fine, spreading branches; uncommon native grass of north-westPoa drummondiana
6Spikelets distinctly laterally compressed, longer than broad; web well-developed; panicle moderately dense and contracted; introduced species7
7Plants bulbous (onion-like) at base from enlarged, fleshy basal sheaths; inflorescence very compact, less than 6 cm long; spikelets 3–6-flowered; mostly dry regions (Murray Mallee and Wimmera)Poa bulbosa
7Plants with swollen lower internodes; inflorescence loosely contracted, mostly more than 6 cm long; spikelets commonly 2 (rarely 3)-flowered; mostly cool, high-rainfall areasPoa trivialis
8Ligule conspicuous, 1 mm long or more, thinly membranous to papery, virtually or quite glabrous9
8Ligule inconspicuous, rarely exceeding 1 mm (occasionally to 1.5 mm in P. clelandii), firm, usually minutely pubescent on the back and at the apex15
9Rhizomatous grass with stiff, glaucous blades and purplish sheaths; lemma entirely glabrous; apparently only Lake Omeo near BenambraPoa orba
9Features not as above10
10Tufted or shortly stoloniferous species, rarely with a short, oblique rhizome; ligule obtuse to acute or jagged at apex11
10Rhizome well-developed; ligule obtuse, entire at apex13
11Plants usually developing short, leafy stolons from base; web well-developed; lemma hairy at least along keel, often distinctly incurved near apex; sheaths usually purplish; exotic grass from well-watered, lowland sitesPoa trivialis
11Plants tufted; web absent; lemma subglabrous to glabrous, not incurved toward apex; sheaths pale; native grasses, typically of high-altitude, usually rocky sites12
12Leaves fine and inrolled-terete, less than 0.5 mm diam.; panicle pyramidal, spreading at maturity; spikelets 2–5 mm longPoa hookeri
12Leaves flat or folded, 2 mm wide or more; panicle narrow and contracted with rather few, plump spikelets, mostly more than 5 mm longSaxipoa saxicola
13Web well-developed; lemma membranous toward apex; glumes unequal, scabrous along keel; widespread exotic grassPoa pratensis
13Web absent; lemma rather firm throughout; glumes subequal, smooth along keel; native grasses of the west and north14
14Leaf-blades flat, thin-textured, scabrous, to 4 mm wide; spikelets to 11 mm long; glumes slightly shorter than lower lemma; heavy, seasonally inundated soils in the northPoa fordeana
14Leaf-blades folded, rather thick, smooth, to 2 mm wide; spikelets to 8 mm long; glumes as long as or slightly exceeding lower lemma; saline lakes of volcanic plainPoa sallacustris
15Lower part of culms and lower (abaxial) surface of leaf-blades scabrous-pubescent to softly pubescent16
15Lower part of culms and lower (abaxial) surface of leaf-blades smooth to scabrous, but not pubescent22
16Blades inrolled, terete or angular in section when fresh; hairs of uniform length17
16Blades flat to closely folded when fresh; hairs often of different lengths21
17Plants producing aerial stolons; blades very fine and thin-textured between the prominent nerves, angular in sectionPoa tenera
17Plants tufted, rarely shortly rhizomatous; blades fine or rather coarse but firm-textured, terete or biconvex in section18
18Blades densely covered with soft, spreading hairs, often appearing whitish; sheaths purplish; rocky areas at high-altitudePoa petrophila
18Blades sparsely to densely pubescent, usually also somewhat scabrous, not or very rarely appearing whitish; sheath pale; lowlands or lower mountains19
19Hairs even, dense and spreading from surfacePoa rodwayi
19Hairs scattered, acutely inclined to surface or occasionally weakly spreading20
20Culms weak, usually lacking nodes between basal leaves and inflorescence, soon lain flat by wind; lemma glabrous between nerves; margins of salt lakes in south-westPoa physoclina
20Culms rarely, if ever, lacking nodes between basal leaves and inflorescence, remaining erect; lemma pubescent to some degree between nerves; widespread grasses, usually of dry forests, woodlands or grasslands (var. hirtella)Poa sieberiana →
21Plants distinctly rhizomatous; sheaths purplish; upper leaf surface sparsely pubescent with scattered fine hairs; montane forests (var. parviflora)Poa hothamensis →
21Plants tufted, rarely shortly rhizomatous; sheaths usually pale; upper leaf surface densely pubescent; mostly lowlandsPoa morrisii
22Plants stoloniferous (young plants tufted), often developing leafy aerial stems; leaves narrow, flaccid, blade flat to angular-terete, mostly c. 0.5 (rarely to 1.5) mm wide, usually with c. 5, raised, smooth or scabrous nerves; culms weak and slender; web absent; principally of damp, shaded situations in the south23
22Plants tufted or rhizomatous; if ever developing leafy aerial stems, other features not as above24
23Leaf-sheath red, connate when young; ligule 0.8–2.6 mm long; lemma glabrous between nerves; restricted to the Brisbane Ranges, and Werribee and Lerderderg GorgesPoa amplexicaulis
23Leaf-sheath usually not red or connate; ligule 0.3–1.5 mm long; lemma with at least some hairs between nervesPoa tenera
24Leaf-blades flat, weakly or closely folded when fresh, the margins often becoming inrolled on drying25
24Leaf-blades narrow and inrolled-terete or inrolled-angular in section33
25Rhizomes developed; lower leaf-sheaths usually distinctly purplish26
25Rhizomes not developed under normal conditions (but, in response to disturbance or in rocky sites, short rhizomes may be produced); lower leaf-sheaths generally pale28
26Culms and sheaths of culm-leaves distinctly compressed; leaves smooth and glabrous, apex keeled, abruptly tapered and often slightly incurved; usually in damper lowlands, but ascending to subalps in the GrampiansPoa clelandii
26Culms and sheaths terete or weakly compressed; leaves scabrous or minutely hairy at least on upper (inner) surface; typically of mountain forests, subalps or alps27
27Leaves distinctly scabrous, blade flat or weakly folded, upper surface scabrous but lacking hairs; web usually well-developed; mainly mountain forestsPoa ensiformis
27Leaves smooth to slightly scabrous, blade generally folded with upper (inner) surface bearing short, fine, sparse to moderately dense hairs; web weakly developed or absent; alps and subalps (var. hothamensis)Poa hothamensis →
28Lemma glabrous, web reduced or absent (var. labillardierei - a form of the volcanic plains)Poa labillardierei →
28Lemma hairy at least along keel in lower part, web various29
29Culm and sheaths of culm-leaves strongly compressed; web absentPoa clelandii
29Culm terete or slightly compressed; web developed30
30Leaves smooth or very minutely scabrous; panicle contracted; mallee or coastal sands31
30Leaves distinctly scabrous; panicle spreading at maturity; rarely truly coastal and not in mallee32
31Leaves normally less than one-half height of plant; spikelets usually dappled purple; lemmas relatively broad, truncate or emarginate at apex; uncommon grass of the north-westPoa lowanensis
31Leaves normally more than one-half height of plant; spikelets normally green or straw-coloured; lemmas narrow, usually rounded at apex; coastal and estuarine foreshores (var. poiformis)Poa poiformis →
32Leaf-blades 3–8 mm wide; lemmas more or less lanceolate in profile; mostly occurring by streams above c. 1000 mPoa helmsii
32Leaf-blades 1–3.5 mm wide; lemmas usually more or less oblong in profile; mostly on alluvial soils below c. 1500 m (var. labillardierei)Poa labillardierei →
33Blades rigid, often sharp-pointed34
33Blades flaccid to firm, but neither rigid nor sharp-pointed43
34Sheaths purplish; blades distinctly scabrous; web well-developed; lemma hairy along the midvein and margins near the base but internerves glabrous; rare grass of subalps (var. acris)Poa labillardierei →
34Plant not combining features as above35
35Inflorescence narrow and contracted at maturity; web copious, or if lacking, lemma glabrous or subglabrous; plants of lowlands36
35Inflorescence pyramidal, with spreading branches at maturity; web not or rarely well-developed, lemma pubescent in lower half or entirely glabrous; alpine or subalpine grasses39
36Web absent or reduced to a very few hairs; lemma glabrous (var. labillardierei - a form of the volcanic plains)Poa labillardierei →
36Web well-developed; lemma usually hairy37
37Entire plant rarely more than 25 cm high; leaves fine (to 0.5 mm diam); inflorescence often almost spike-like, to 4 cm long; rhizomatous or sometimes stoloniferous or tufted; coastal, mostly on calcareous sands or sands overlying basaltPoa halmaturina
37Plant generally exceeding 25 cm in height; leaves relatively coarse (>0.5 mm diam.); inflorescence open to contracted, but hardly spike-like, longer than 4 cm; plants normally tufted (but branching from the lower nodes in P. poiformis var. ramifer)38
38Leaves normally less than one-half height of plant; spikelets usually dappled purple; lemmas relatively broad, truncate or emarginate at apex; uncommon grass of north-westPoa lowanensis
38Leaves normally more than one-half height of plant; spikelets normally green or straw-coloured; lemmas narrow, usually rounded at apex; coastal and estuarine foreshores (var. poiformis)Poa poiformis →
39Leaves bright green; sheath not or rarely purplish; moister sites, including bogs and creek marginsPoa costiniana
39Leaves slightly to strongly glaucous; sheath commonly red or purplish; mostly of drier sites40
40Lemmas distinctly hairy on the internerves in the lower half; plants sometimes shortly stoloniferous41
40Lemmas virtually or quite glabrous on the internerves throughout42
41Blades smooth to the touch, often curved, very stiff and sharp-pointedPoa fawcettiae
41Blades distinctly scabrous, not particularly stiffPoa phillipsiana
42Lemmas hairy along keel and often lateral nerves; web present or absent; strictly tufted; blades usually more than 15 cm long; Mt BuffaloPoa costiniana
42Lemmas entirely glabrous, occasionally the web very weakly developed; usually shortly stoloniferous with several-branched, ascending stems; blades not more than 15 cm long; Macalister and Howqua River catchmentsPoa orthoclada
43Lemmas virtually or quite glabrous on the internerves throughout, sometimes with some hairs along keel and lateral nerves44
43Lemmas distinctly hairy on the internerves in the lower half47
44Web present (var. labillaridierei)Poa labillardierei →
44Web absent (occasionally a few weak hairs present)45
45Blades smooth, usually bluish; sheaths purplish; junction of blade and sheath not produced into a knob-like swelling; ligules prominently ciliate; usually shortly stoloniferous with several-branched, ascending stems; Macalister and Howqua River catchmentsPoa orthoclada
45Blades somewhat scabrous, rarely bluish; sheaths pale (or purplish in P. meionectes); junction of blade and sheath commonly produced into a distinct knob-like swelling; ligules microscopically ciliate only; tufted plants; mostly East Gippsland46
46Glumes relatively broad; lemmas 3–4.5 mm long; leaves often somewhat firm, not shining, nerves usually inconspicuous; highlandsPoa clivicola
46Glumes narrow (relative to lemmas); lemmas 2–3.5 mm long; leaves very fine, often shining, with raised nerves; lowlandsPoa meionectes
48Leaves green to grey-green but not bluish; plants always tufted; very common, widespread (var. sieberiana)Poa sieberiana →
48Leaves distinctly bluish; plants sometimes shortly stoloniferous; montane to alpine areas49
49Sheaths purplish; ligule very short and inconspicuous; tussock often relatively slender; higher alpsPoa phillipsiana
49Sheaths pale; ligule occasionally to c. 1 mm long; lemma sometimes sub-glabrous; tussock usually densely leafy; montane areas, mostly in northeast (var. cyanophylla)Poa sieberiana →
50Blades usually somewhat firm, bluish; at least some sheaths purplish; plants sometimes shortly stoloniferousPoa fawcettiae
50Blades very soft, bright green to somewhat grey-green but not bluish; sheaths not purplishPoa hiemata
From: Walsh, N.G. (1994). Poaceae. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria. Vol. 2. Ferns and Allied Plants, Conifers and Monocotyledons. Inkata Press, Melbourne.