GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Holcus gayanus

HABIT Annual. Culms geniculately ascending, or decumbent; 8–40(–75) cm long. Culm-nodes glabrous. Leaf-sheaths loose; pubescent. Ligule an eciliate membrane; 1–2.5 mm long; pubescent on abaxial surface; erose, or lacerate. Leaf-blades flat, or convolute; 3–40 cm long; 0.5–3 mm wide; mid-green, or grey-green. Leaf-blade surface pubescent.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; oblong; 1–6 cm long; 1–2 cm wide. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets elliptic, or oblong; laterally compressed; 6–11 mm long; falling entire; readily shedding fertile florets. Floret callus pubescent.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 5.5–8.5 mm long; 0.75–1 length of upper glume; chartaceous; 1-keeled; 1 -veined. Lower glume primary vein scaberulous. Lower glume lateral veins absent. Lower glume apex setaceously attenuate. Upper glume lanceolate, or ovate; 6–11 mm long; 2.5–3.5 length of adjacent fertile lemma; chartaceous; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume surface scabrous; rough on veins. Upper glume apex setaceously attenuate.

FLORETS Fertile florets all alike, or with the lowest dissimilar. Lowest fertile lemma muticous, or awned. Fertile lemma ovate; 2.4–3 mm long; cartilaginous; shiny; without keel; 5 -veined. Lemma apex acute; awned; 1 -awned. Principal lemma awn subapical; geniculate; 6–8 mm long overall; clearly exserted from spikelet; with twisted column. Palea 1 length of lemma. Rhachilla extension 0.3 mm long; pubescent.

FLOWER Anthers 3; 2–2.5 mm long. Ovary glabrous.

FRUIT Caryopsis 2 mm long.

DISTRIBUTION Europe: southwestern.

NOTES Aveneae. Gr Extremadura.

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