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.

Avena sterilis

HABIT Annual. Culms geniculately ascending, or decumbent; 30–180 cm long; 2–5 -noded. Leaves cauline. Ligule an eciliate membrane; 3–8 mm long. Leaf-blades 10–60 cm long; 4–18 mm wide. Leaf-blade surface scaberulous; rough adaxially. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; effuse; nodding; 10–45 cm long; 5–25 cm wide. Primary panicle branches drooping. Panicle branches scaberulous.

Spikelets pendulous; solitary. Fertile spikelets pedicelled. Pedicels filiform; 5–35 mm long.

FERTILE SPIKELETS Spikelets comprising 2–5 fertile florets; with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 23–50 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Floret callus evident; bearded; obtuse; disarticulating obliquely. Floret callus hairs 0.15 length of lemma.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 23–50 mm long; 1 length of upper glume; membranous; without keels; 7–11 -veined. Lower glume apex acuminate. Upper glume lanceolate; 23–50 mm long; 1.2–1.4 length of adjacent fertile lemma; membranous; without keels; 7–11 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 15–40 mm long; coriaceous; much thinner above; without keel; 7 -veined. Lemma surface scaberulous; rough above; pilose; hairy below. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 30–80 mm long overall; with twisted column. Column of lemma awn hispidulous to pubescent. Palea keels ciliate.

FLOWER Anthers 3; 2.5–4 mm long. Ovary pubescent all over.

FRUIT Caryopsis with adherent pericarp; 11–12 mm long; hairy all over. Hilum linear.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, west tropical, northeast tropical, east tropical, and south. Asia-temperate: Soviet Middle Asia, Caucasus, western Asia, Arabia, and China. Asia-tropical: India. Australasia: Australia and New Zealand. North America: eastern Canada. South America: western South America, Brazil, and southern South America.

NOTES Aveneae. FTEA.

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