Poa bulbosa

HABIT Perennial; caespitose. Butt sheaths thickened and forming a bulb. Culms erect, or geniculately ascending; 5–40 cm long; 2–4 -noded. Culm-internodes terete; smooth. Lateral branches lacking. Leaves mostly basal. Leaf-sheaths smooth. Ligule an eciliate membrane; 2–4 mm long; obtuse, or acute. Leaf-blades flat, or conduplicate; 1–10 cm long; 1–2 mm wide. Leaf-blade surface smooth; glabrous. Leaf-blade margins scaberulous. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong, or ovate; dense; 2–6 cm long; 1–2.5 cm wide. Primary panicle branches ascending. Panicle branches capillary; scaberulous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.3–3 mm long.

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

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 2–3 mm long; 1 length of upper glume; membranous; much thinner on margins; 1-keeled; 1–3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume ovate; 2–3 mm long; 0.8–0.9 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma ovate; lanceolate in profile; 2.5–3.5 mm long; membranous; much thinner above; keeled; 5 -veined. Lemma midvein ciliate; hairy below. Lemma lateral veins stopping well short of apex. Lemma surface scaberulous; pubescent; hairy on veins. Lemma margins ciliate; hairy below. Lemma apex acute. Palea 1 length of lemma. Palea keels ciliolate; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 1–1.5 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

CLEISTOGENES AND VIVIPARY Vegetative proliferation occurs.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, northeast tropical, and south. Asia-temperate: Siberia, Soviet Middle Asia, Caucasus, western Asia, Arabia, and China. Asia-tropical: India. Australasia: Australia and New Zealand. North America: western Canada, northwest USA, north-central USA, northeast USA, southwest 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.