Avena sativa

HABIT Annual. Culms erect; 40–180 cm long. Leaves cauline. Ligule an eciliate membrane; 3–6 mm long. Leaf-blades 14–40 cm long; 5–15 mm wide. Leaf-blade surface scaberulous; rough on both sides. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; effuse; nodding; 20–40 cm long; 5–15 cm wide. Primary panicle branches drooping.

Spikelets pendulous; solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets cuneate; laterally compressed; 22–27 mm long; persistent on plant. Floret callus glabrous; disarticulating obliquely.

GLUMES Glumes similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 22–27 mm long; 1 length of upper glume; membranous; without keels; 7–9 -veined. Lower glume apex acuminate. Upper glume lanceolate; 22–27 mm long; 1.5–1.6 length of adjacent fertile lemma; membranous; without keels; 7–9 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 15–17 mm long; coriaceous; much thinner above; without keel; 7–9 -veined. Lemma surface scabrous; rough above; glabrous. Lemma apex dentate; 2 -fid; muticous, or awned; 0–1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 25–35 mm long overall; with twisted column. Palea keels ciliate.

FLOWER Anthers 3. Ovary pubescent all over.

FRUIT Caryopsis with adherent pericarp; hairy all over. Hilum linear.

DISTRIBUTION Europe: northern, central, southwestern, southeastern, and eastern. Africa: north, Macaronesia, northeast tropical, east tropical, southern tropical, south, and middle Atlantic ocean. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, Arabia, China, Mongolia, and eastern Asia. Asia-tropical: India, Indo-China, and Malesia. Australasia: Australia and New Zealand. Pacific: southwestern, south-central, northwestern, and north-central. North America: Subarctic, northwest USA, north-central USA, northeast USA, southwest USA, south-central USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Aveneae. Fl Turk.

ADDITIONAL CHARACTERS Floret callus fracturing transversely.

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