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 pentapolitana

HABIT Annual; caespitose. Culms erect, or geniculately ascending; 8–15 cm long. Lateral branches lacking. Leaf-sheaths smooth; glabrous on surface. Ligule an eciliate membrane; 1–1.5 mm long; obtuse. Leaf-blades flat, or conduplicate; 3–5 cm long; 1.5–3 mm wide. Leaf-blade surface glabrous. Leaf-blade margins smooth. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; dense; 2–3 cm long. Primary panicle branches spreading; 2–3 -nate; 0.5–1.5 cm long. Panicle branches smooth.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets ovate; laterally compressed; 2–2.5 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 oblong; 1.6–1.8 mm long; 0.9 length of upper glume; membranous; much thinner on margins; purple; 1-keeled; 3 -veined. Lower glume primary vein scabrous. Lower glume apex acute. Upper glume lanceolate; 1.7–2 mm long; 1.1 length of adjacent fertile lemma; membranous; with hyaline margins; purple; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acute.

FLORETS Fertile lemma ovate; elliptic in profile; 1.6–1.8 mm long; membranous; purple; streaked with last colour and tipped with last colour; keeled; 5 -veined. Lemma midvein scaberulous. Lemma surface glabrous. Lemma apex obtuse, or acute. Palea 1 length of lemma. Palea keels scaberulous; adorned above.

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

FRUIT Caryopsis with adherent pericarp. Hilum punctiform.

DISTRIBUTION Africa: north.

NOTES Poeae. Scholz 1994.

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