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.

Avena vaviloviana

HABIT Annual. Culms erect, or geniculately ascending; 80–110 cm long; 3–5 -noded. Lateral branches lacking. Leaf-sheaths glabrous on surface, or puberulous. Ligule an eciliate membrane; 4–7 mm long; erose. Leaf-blades 15–30 cm long; 5–10 mm wide. Leaf-blade surface scaberulous; glabrous, or puberulous. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; elliptic; nodding; 20–40 cm long; 5–15 cm wide.

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

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 18–25 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose; with 2–3 mm long hairs. Floret callus evident; bearded; obtuse; disarticulating transversely; with circular scar. Floret callus hairs 1–5 mm long.

GLUMES Glumes persistent; similar; exceeding apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 18–25 mm long; 1 length of upper glume; membranous; without keels; 7–9 -veined. Lower glume apex acuminate. Upper glume elliptic; 18–25 mm long; 1.5 length of adjacent fertile lemma; membranous; without keels; 7–9 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 12–15 mm long; coriaceous; much thinner above; without keel; 7 -veined. Lemma surface scaberulous; rough above and on veins; glabrous, or pilose. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 20–30 mm long overall; with twisted column. Column of lemma awn 8–12 mm long. Lateral lemma awns arising on apex of lobes; 1–2 mm long; shorter than principal. Palea keels winged; narrowly winged; ciliolate.

FLOWER Anthers 3; 1–2 mm long. Ovary pubescent all over.

FRUIT Caryopsis with adherent pericarp; sulcate on hilar side; 6 mm long; hairy all over. Hilum linear.

DISTRIBUTION Africa: northeast tropical.

NOTES Aveneae. FTA 1993.

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