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.

Ventenata dubia

HABIT Annual; caespitose. Culms 20–55 cm long. Ligule an eciliate membrane; 5–6 mm long; lacerate; acute. Leaf-blades 2–6 cm long; 0.8–3 mm wide. Leaf-blade surface pubescent; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 7–20 cm long. Primary panicle branches 4–10 cm long; bearing 2–5 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels cuneate; 2–17 mm long; scabrous.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 10–16 mm long; breaking up at maturity; disarticulating between fertile florets but the lowest falling with glumes attached. Floret callus evident; 0.5 mm long; pubescent.

GLUMES Glumes deciduous with pedicel attached; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 4.5–7 mm long; 0.6–0.7 length of upper glume; membranous; 1-keeled; 7 -veined. Lower glume lateral veins ribbed. Lower glume apex acuminate. Upper glume lanceolate; 6.3–11 mm long; 0.7–1 length of adjacent fertile lemma; membranous; 1-keeled; 9 -veined. Upper glume lateral veins ribbed. Upper glume apex acuminate.

FLORETS Fertile florets with the lowest dissimilar. Lowest fertile lemma elliptic; 1.25 length of adjacent lemma; thinner than adjacent lemma; awned (terminal, 2–3mm). Fertile lemma elliptic; 5–13 mm long; coriaceous; without keel; 5 -veined. Lemma apex lobed; 2 -fid; incised 0.1 of lemma length; awned; 3 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 20–25 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 2–3 mm long; shorter than principal. Palea 0.9 length of lemma. Palea keels ciliate. Rhachilla extension 0.1–0.2 length of fertile floret.

FLOWER Anthers 3; 1–2 mm long. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp; ellipsoid. Endosperm liquid.

DISTRIBUTION Europe: central, southwestern, southeastern, and eastern. Africa: north. Asia-temperate: Caucasus and western Asia.

NOTES Aveneae. WDC.

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