GrassBase - The Online World Grass Flora

Descriptions

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

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

Poa acroleuca

HABIT Annual; caespitose. Culms erect; 25–50 cm long; 0.8–2 mm diam.; 3–5 -noded. Culm-internodes 3–15 cm long. Leaf-sheaths tubular for much of their length; with 1 of their length closed; smooth, or scaberulous. Ligule an eciliate membrane; 0.5–1 mm long; white; obtuse. Leaf-blades 7–15 cm long; 2–6 mm wide. Leaf-blade surface smooth, or scaberulous; rough adaxially. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 8–20 cm long; 4–6 cm wide. Primary panicle branches spreading; 2–5 -nate; 4–9 cm long. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2 mm long.

FERTILE SPIKELETS Spikelets comprising 3–6 fertile florets; with diminished florets at the apex. Spikelets ovate; laterally compressed; 2.5–5.5 mm long; 1.2–1.8 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1–1.5 mm long; smooth. Floret callus woolly. Floret callus hairs 0.25–0.33 length of lemma.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 1.5–2.2 mm long; 0.75 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume primary vein scabrous. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume elliptic; 2–2.8 mm long; 0.75–1 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface scabrous; rough on veins. Upper glume apex acute.

FLORETS Fertile lemma ovate; elliptic in profile; 2–3.5 mm long; membranous; much thinner above; much thinner on margins; keeled; 5 -veined. Lemma lateral veins with distinct primaries but obscure intermediates. Lemma surface pubescent; hairy below; hairy on veins. Lemma apex obtuse. Palea 1 length of lemma. Palea keels ciliolate; adorned all along. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.8–1 mm long.

FRUIT Caryopsis with adherent pericarp; oblanceolate; 1.5 mm long. Hilum punctiform.

DISTRIBUTION Asia-temperate: Soviet far east, China, and eastern Asia.

NOTES Poeae. Koyama 1994.

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