GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Poa pusilla

HABIT Perennial; caespitose. Rhizomes elongated. Basal innovations extravaginal. Culms slender; 5–35 cm long. Lateral branches lacking. Leaf-sheaths keeled; glabrous on surface. Ligule a ciliolate membrane; 0.2–0.5 mm long; pubescent on abaxial surface; truncate. Leaf-blades involute; 5–15 cm long; 0.5–1 mm wide; flaccid; light green. Leaf-blade surface pubescent; sparsely hairy; hairy adaxially. Leaf-blade apex obtuse, or abruptly acute.

INFLORESCENCE Inflorescence a panicle. Peduncle smooth.

Panicle open; 1.5–8.5 cm long. Primary panicle branches spreading; bearing 1–4 fertile spikelets on each lower branch. Panicle branches capillary; scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–5 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 3–7.5 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.6–0.8 mm long; sparsely hairy. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate, or elliptic; 2–4 mm long; 1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scaberulous. Lower glume surface smooth, or asperulous; rough on veins. Lower glume apex acute. Upper glume lanceolate, or elliptic; 2–4 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scaberulous. Upper glume surface smooth, or asperulous; rough on veins. Upper glume apex acute.

FLORETS Fertile lemma oblong, or ovate; elliptic in profile; 2–4 mm long; membranous; much thinner on margins; keeled; 5 -veined. Lemma midvein without distinctive roughness, or scaberulous; ciliate; hairy below. Lemma surface smooth, or scaberulous; rough between veins; pilose; hairy below; hairy on veins. Lemma apex obtuse. Palea 2–3.5 mm long. Palea keels scaberulous; adorned above. Palea surface puberulous; hairy on back.

FLOWER Lodicules 2; 0.5 mm long; membranous. Anthers 3; 1–2 mm long.

FRUIT Caryopsis with adherent pericarp; 1 mm long. Hilum punctiform.

DISTRIBUTION Australasia: New Zealand.

NOTES Poeae. Edgar 1995.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.