Alpine Bluegrass

Foodplant / parasite
Blumeria graminis parasitises live Poa alpina

This species has spikelets broadly ovate, lower glumes 3-veined, lemma proximally pubescent between veins, callus glabrous, old sheaths persistent and closely overlapping, anthers more than 1.2 mm, and palea keels shortly villous, together making it quite distinct from other species. Gatherings from arctic regions and European mountains are often viviparous, but such plants have not been recorded from China.

Plants of Alpine Meadow-grass with proliferating spikelets are occasionally found. 2700-5500m.

Perennials, densely tufted; shoots intravaginal. Culms erect or obliquely ascending, (5–)10–30(–45) cm tall, usually several per tuft, smooth, nodes often 2, 1 exserted. Leaf sheath smooth, glabrous, 2 or more × as long as blade, basal ones persistent, investing culm bases, uppermost closed for 1/4 length; ligule white, 2–4(–5) mm, abaxially smooth, of tillers 1–2 cm long; blade grayish green, flat or folded, thickly papery, withering, 3–10(–16) cm, 2–6 mm wide, surfaces glabrous, margins smooth or sparsely scabrid, apex prow-tipped. Panicle loosely contracted to open, ovoid to oblong (pyramidal at anthesis), 2–7 × 2–3 cm, purple tinged; branches ascending to spreading, 2 per node, rounded, smooth or distally sparsely scabrid, longest 2(–3) cm, divaricately rebranched with moderately crowded spikelets in distal 1/2. Spikelets broadly ovate, 4–8 mm, florets 3–5(–7); vivipary absent in China; rachilla internodes ca. 0.5 mm, smooth, glabrous (rarely slightly pilulose); glumes broadly ovate, membranous-papery, subequal, faintly 3-veined, keel arched, scabrid, surfaces smooth, margins membranous, smooth, apex acute, lower glume 2.5–3(–4) mm, upper glume 3.4–4.5 mm; lemmas broadly ovate, membranous-papery, apex and margins broadly membranous, keel arched, keel villous for 2/3 of length, marginal veins for 1/2 length, intermediate veins indistinct, area between veins pilulose to short villous; callus glabrous; palea glabrous or proximally infrequently pilulose between keels, keels scabrid, often medially pilulose to shortly villous. Anthers 1.2–2 mm. Fl. and fr. Jul–Sep. 2n = 22, 28, 32, 33, 34, 35, 42, 44, 58.

Tufted perennial; culms 15-30(-40)cm high, erect or ascending, thickened at the base with the fibrous remains of old leaf-sheaths but these not forming a bulbous swelling. Leaf-blades flat, 4-12cm long, 2-5mm wide, abruptly contracted to a hooded tip, scaberulous on the margins; ligule often lacerate, 3-5mm long Panicle ovate to pyramidal, 3-7cm long, compact or ± spreading; branches mostly paired, scaberulous. Spikelets 4-6(-9)-flowered, broadly ovate, 4-7mm long, tinged with purple; glumes unequal, ovate to elliptic, the lower 2.5-4mm long, 1-3-nerved, the upper 3-4.5mm long, 3-nerved; lemmas oblong or narrowly elliptic in side-view, 3.5-5mm long, subacute, ciliate on the keel and marginal nerves, sparsely hairy on the surface between the nerves, usually with a little wool at the base; palea as long as the lemma, the keels ciliate below, scabrid above; anthers 1.5-2.5mm long.

Arctic, mountains of Europe & Asia east to Nepal, Tibet & Mongolia, N. America.

Qinghai, Xinjiang, Xizang [Afghanistan, India, Japan, Kazakhstan, Kyrgyzstan, Nepal, Pakistan, Russia, Tajikistan; SW Asia (Iran), Europe, North America].

Distribution: Pakistan (N.W.F.P., Gilgit & Kashmir); on mountains in Europe and the Mediterranean region through the Middle East to Central Asia and India; North America.

3800 m

Fl. & Fr. Per.: June-September.

Low arctic to subalpine meadows, sporadic in taiga, slopes, crevices along ditch banks, sandy places; 2400–3800 m.

Perennials, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence lax, widely spreading, branches drooping, pendulous, Inflorescence with 2-10 branches, Inflorescence branches more than 10 to numerous, Flowers bisexual, Flowers replaced by bulbils, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 2 florets, Spikelets with 3-7 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes keeled or winged, Glumes 3 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 5-7 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stam ens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Poa alpina, commonly known as alpine meadow-grass or alpine bluegrass, is a species of grass with a primarily holarctic distribution.

It is noted for being pseudoviviparous: in place of seeds, it sometimes reproduces asexually, creating new plantlets in the spikelets.

In Montana, USA

Spiklets with hairy lemmas