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Poa annua L. |
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Graminae |
Author: Alain Peeters |
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Annual meadowgrass (English), Pâturin annuel (French), Einjähriges rispengras (German). Annual plant, small size, hairless, cespitous. Stems creeping to creeping-ascendent, sometimes rooted at the nodes, or erect, 5 - 25 cm high. Blade folded when young, soft, 2 - 5 mm. wide, flat, yellowish-green, often accordion-pleated in the top third, with 2 well visible veins on each side of the central nerve (<< ski tracks >>) and with a hooded tip. Ligule visible, 2 - 5 mm long, white. No auricles. Panicle-like inflorescence, pyramidal, few branches but all oriented to one side of the axis (180°). Spikelets 3 - 6 - flowered, without woolly hairs at the base. The weight of 1000 seeds is 0.2 to 0.3 g (small seeds). Chromosome number: 2n = 28. Large climate range. Survives extreme weather periods thanks to its seeds buried in the soil. Optimum on normally drained to cool soils, but large range. Optimum on nutrient-rich soils, neutral to slightly acid but large range. All soil types. Subcosmopolitan but only in altitude in tropical areas. From the lowlands to the highlands. |