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 bactriana

HABIT Perennial; caespitose. Butt sheaths thickened and forming a bulb. Culms erect; 10–70 cm long. Culm-internodes terete; smooth. Lateral branches lacking. Leaves mostly basal. Ligule an eciliate membrane; 1.5–3 mm long; obtuse. Leaf-blades flat, or conduplicate; 1.5–17 cm long; 1–3.5 mm wide. Leaf-blade surface smooth, or scaberulous. Leaf-blade margins scabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong, or pyramidal; dense, or loose; 1.5–10 cm long. Primary panicle branches ascending; (1–)2–3(–4) -nate. Panicle branches smooth.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–4(–6) fertile florets; with diminished florets at the apex. Spikelets elliptic, or ovate; laterally compressed; (3–)3.5–7 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes smooth. Floret callus glabrous.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 2–3(–3.5) mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume ovate; 2–3(–3.5) mm long; 0.9–1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma ovate; elliptic in profile; 2–3.5(–4) mm long; membranous; keeled; 5 -veined. Lemma midvein without distinctive roughness, or scaberulous. Lemma margins without distinctive roughness, or scaberulous. Lemma apex obtuse, or acute. Palea 0.9 length of lemma. Palea keels scabrous; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3; 0.6–2 mm long.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Asia-temperate: Soviet Middle Asia, western Asia, and China. Asia-tropical: India.

NOTES Poeae. Fl Pak.

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