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Species
Poa annua var. reptans
IUCN
NCBI
EOL Text
Tufted annual or short-lived perennial; culms 5-30cm high, erect, spreading or prostrate, sometimes with a creeping base rooting from the nodes, slightly compressed. Leaf-blades flat or folded, 1-14cm long, 1–2(–5)mm wide, flaccid, abruptly tapered to a pointed or bluntly hooded tip, often transversely wrinkled, scaberulous on the margins; ligule blunt, 2–5mm long. Panicle ovate or pyramidal, (1–)3–8(–12)cm long, loose or rather dense; branches paired, spreading or de-flexed after anthesis, smooth. Spikelets with 3–5(-10) closely spaced florets, ovate or oblong, 3–10mm long, pale or bright green, reddish or purplish; glume unequal, the lower lanceolate to ovate, 1.5–3mm long, 1–nerved, the upper elliptic or oblong, 2–4mm long, 3–nerved; lemmas semi-elliptic or oblong in side-view, 2.5–4mm long, blunt, glabrous or sparsely to densely ciliate on the keel and nerves, without any wool at the base; palea nearly as long as the lemma, ciliate all along the keels; anthers 0.6–0.8(–1)mm long.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=200025985 |
Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems mat or turf forming, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stems compressed, flattened, or sulcate, Stems branching above base or distally at nodes, 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 c onspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath or blade keeled, 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 blade margins folded, involute, or conduplicate, 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 with 2-10 branches, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 3-7 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spike lets 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, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Compiled from several sources by Dr. David Bogler, Missouri Botanical Garden in collaboration with the USDA NRCS NPDC |
Source | http://plants.usda.gov/java/profile?symbol=POAN |
Annuals, sometimes over wintering, infrequently stoloniferous. Culms loosely tufted, erect or oblique, often decumbent, often geniculate, soft, 6–30(–45) cm tall, smooth, nodes 1 or 2(or 3), 1(or 2) exserted. Leaf sheath slightly compressed, thin, smooth, uppermost closed for ca. 1/3 of length; blade light to dark green, flat or folded, thin, 2–12 cm × (0.8–)1–3.5 mm, margins slightly scabrid, apex acutely prow-tipped; ligules 0.6–3 mm, abaxially smooth, glabrous, apex obtuse, margin irregularly dentate, smooth. Panicle open, moderately congested, broadly ovoid to pyramidal, (1–)3–10 cm, as long as wide; branches ascending, spreading, or a few reflexed, 1 or 2(–3) per node, smooth, longest with usually 3–5 spikelets in distal 1/2. Spikelets ovate to oblong, dark to light green, (3–)4–5.5 mm, florets 3–5, distal fertile florets often female; vivipary absent; rachilla internodes 0.5–1.5 mm, smooth, glabrous, hidden or exposed; glumes unequal, smooth or rarely keeled with hooks, lower glume lanceolate and acute to subflabellate and obtuse, 1.5–2(–3) mm, 1-veined, upper glume elliptic, 2–3(–4) mm, 3-veined, the margin angled; lemmas ovate, 2.2–3.5 mm, apex and margins broadly membranous, intermediate veins prominent, keel and marginal, and usually intermediate, veins villous in the lower 1/2, rarely glabrous throughout; callus glabrous; palea keels smooth, densely pilulose to short villous. Anthers 0.6–1 mm, usually at least 2 × as long as wide, or vestigial. Fl. Apr–May, fr. Apr–Jul. 2n = 28.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200025985 |
Annual Meadow-grass is a very common weedy species found in a variety of habitats. 1400-4300m.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=5&taxon_id=200025985 |
This dwarf grass is easy to overlook, particularly when it grows in close proximity to other grasses. For a Poa sp. (bluegrass), it has short leaf blades and rather plump-looking seedheads. It is fairly easy to identify because of its small size and low sprawling stems. To determine the technical characteristics of this and other bluegrasses, it is highly desirable to use a good 10x hand lens, or even a field microscope. Such instruments can be used to detect the presence (or absence) of hairs along the veins and bases of the lemmas. Some bluegrasses superficially resemble Eragrostis spp. (love grasses), but the latter have tufts of hair at the junctions of their blades and sheaths. Bluegrasses lack such tufts of hair.
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Copyright © 2002-2014 by Dr. John Hilty |
Source | http://www.illinoiswildflowers.info/grasses/plants/an_bluegrass.htm |
7.5 Plasticidad ambiental y tolerancia
tolera pH de 4.8 a 8.0, su precipitación mínima es de 600 mm, no tolera la salinidad y su tolerancia a la sombra es intermedia, su resistencia a la sequía y al fuego es baja.
4.4 Conducta
maleza.
License | http://creativecommons.org/licenses/by-nc-sa/2.5/ |
Rights holder/Author | CONABIO |
Source | No source database. |
Poa annua is easily distinguished from other short-anthered Poa, other than P. infirma, by the annual habit, absence of a web on the callus, and the near absence of hooks on the panicle branches and spikelet bracts, in combination with densely pubescent palea keels that lack hooked prickle hairs at the apex. Plants with glabrous florets are sporadically encountered.
Plants perennating by short stolons rooting at the nodes appear to develop repeatedly but sporadically at various elevations with prolonged, cool, mesic growing conditions, possibly in response to trampling. These are sometimes placed in var. reptans. Such plants have been recorded from Yunnan.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
Source | http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200025985 |
This grass is a spring or fall annual that completes its life cycle within a short period of time (about 6 weeks). It is usually quite small, consisting of a low tuft of vegetation about 4" across and 1½" tall. However, substantially larger plants are sometimes observed. The typical plant has sprawling culms about 2½" long that are unbranched, except at the base. They are light green, glabrous, terete, and largely covered by the sheaths. The blades of the alternate leaves are 1½" long and 2-3 mm. across; they are dull to bright green, hairless, and keel-shaped at their tips. The leaf sheaths are light to medium green, hairless, open, and longitudinally veined. At the junctions of sheaths and blades, the ligules consist of short chaffy membranes.
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | Copyright © 2002-2014 by Dr. John Hilty |
Source | http://www.illinoiswildflowers.info/grasses/plants/an_bluegrass.htm |
"Annuals; culms 15-20 cm high, tufted; nodes glabrous. Leaves 5-10 x 0.2-0.3 cm; rounded at base, glabrous; sheath keeled, glabrous; ligule membranous. Panicle 5-6 x 2 cm, contracted; branches filiform, glabrous. Spikelets similar, 5-6 mm long, ovate, glabrous; lower glume 2 x 0.5 mm, lanceolate, 1-nerved; upper glume 2.5 x 1 mm, ovate, acute, 3-nerved; florets 2-4, similar; upper florets exerted; lemmas 3 x 1 mm, ovate-lanceolate, 3-5-nerved, hairy along the nerves; palea 3 x 0.75 mm, lanceolate, 2-nerved; stamens 3; ovary oblong; style short or absent."
Flowering and fruiting: July-September