Poa nemoralis

HABIT Perennial; caespitose. Butt sheaths herbaceous. Culms erect, or geniculately ascending; 15–90 cm long; 3–5 -noded. Culm-internodes terete; smooth. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths keeled; smooth. Ligule an eciliate membrane; 0.1–0.5 mm long; truncate. Leaf-blades 5–12 cm long; 1–3 mm wide; flaccid. Leaf-blade surface smooth, or scaberulous; glabrous. Leaf-blade apex abruptly acute, or acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate, or oblong, or ovate; effuse; 3–20 cm long. Primary panicle branches spreading. Panicle branches flexuous; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.5–6 mm long.

FERTILE SPIKELETS Spikelets comprising 1–5 fertile florets; with diminished florets at the apex. Spikelets oblong, or ovate; laterally compressed; 3–6 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes obscured by lemmas; smooth. Floret callus glabrous, or woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 2–3 mm long; 0.8–1 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume lanceolate, or oblong, or ovate; 2.5–3.5 mm long; 0.9–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma ovate; elliptic in profile; 2.6–3.6 mm long; membranous; much thinner above; much thinner on margins; keeled; 5 -veined. Lemma midvein ciliolate; hairy below. Lemma lateral veins stopping well short of apex. Lemma surface pubescent; hairy on back, or on veins. Lemma margins ciliate; hairy below. Lemma apex acute. Palea 1 length of lemma. Palea keels scaberulous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 1.3–2 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, China, Mongolia, and eastern Asia. Asia-tropical: India. Australasia: New Zealand. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, and southeast USA. South America: southern South America.

NOTES Poeae. CEH.

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