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.

Helictotrichon imberbe

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 30–100 cm long; 2–3 -noded. Lateral branches lacking. Leaf-sheaths smooth; pubescent. Ligule an eciliate membrane; 1–1.5 mm long; truncate. Leaf-blades 5–15 cm long; 1.5–6 mm wide. Leaf-blade surface scaberulous; rough adaxially; glabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; linear; continuous, or interrupted; equilateral, or nodding; 7–30 cm long. Primary panicle branches 2–5 cm long. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 10–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; pilose; hairy at tip; with 2–3 mm long hairs. Floret callus 0.6 mm long; pilose. Floret callus hairs 1.5 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume lanceolate; 5–7 mm long; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 7–9 mm long; 1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 7–8 mm long; cartilaginous; without keel; 5 -veined. Lemma surface granulose; rough above. Lemma apex dentate; 2 -fid; awned; 3 -awned. Principal lemma awn dorsal; arising 0.66 way up back of lemma; geniculate; 15–19 mm long overall; with twisted column. Column of lemma awn 5–7 mm long. Lateral lemma awns arising on apex of lobes; 1 mm long. Palea 6 mm long. Palea keels ciliolate.

FLOWER Anthers 3; 0.7–1 mm long; retained within floret. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp; 2.5 mm long; hairy at apex. Hilum linear.

DISTRIBUTION Africa: south.

NOTES Aveneae. =Helictotrichon turgidulum. Schweickerdt 1993.

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