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 urssulensis

HABIT Perennial; caespitose; clumped loosely, or moderately. Culms 20–60 cm long; with 0.33–0.5 of their length below uppermost node. Culm-internodes terete; antrorsely scabrous. Lateral branches lacking. Leaf-sheaths open for most of their length; smooth. Ligule an eciliate membrane; 0.2–1.5 mm long. Leaf-blades 5–20 cm long; 1.3–3.5 mm wide. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong, or ovate; 10–30 cm long. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–5 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; scaberulous; glabrous. Floret callus woolly.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume lanceolate; 0.8–1 length of upper glume; membranous; 1-keeled; 1–3 -veined. Lower glume apex acuminate. Upper glume elliptic, or ovate; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma ovate; 3.2–4 mm long; membranous; much thinner above; much thinner on margins; keeled; 5 -veined. Lemma lateral veins stopping well short of apex. Lemma apex acute. Palea 1 length of lemma. Palea keels scabrous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; membranous. Anthers 3.

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Europe: eastern. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, China, Mongolia, and eastern Asia.

NOTES Poeae. Zlaki 1997.

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