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.

Periballia laevis

HABIT Annual. Culms 10–35 cm long. Ligule an eciliate membrane. Leaf-blades 1–4 cm long; 1–2 mm wide.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 2–6 cm long. Panicle branches capillary.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; glabrous; tip pyriform.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 2 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite. Floret callus pilose. Floret callus hairs 0.1–0.2 length of lemma.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume elliptic; 1.5–1.7 mm long; 1 length of upper glume; hyaline; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 1.5–1.7 mm long; 0.8 length of adjacent fertile lemma; hyaline; 1-keeled; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute.

FLORETS Fertile lemma oblong; 2 mm long; membranous; without keel; 5 -veined. Lemma midvein scaberulous. Lemma apex obtuse; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5–0.6 way up back of lemma; straight; 1 mm long overall; not or scarcely exserted from spikelet. Palea 1 length of lemma.

FLOWER Anthers 3; 0.1–0.3 mm long.

FRUIT Endosperm farinose.

DISTRIBUTION Europe: southwestern and eastern. Africa: north.

NOTES Aveneae. Fl Eur.

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