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 delavayi

HABIT Perennial. Culms erect; 15–35 cm long; 2–3 -noded. Culm-internodes distally glabrous. Lateral branches lacking. Leaf-sheaths mostly shorter than adjacent culm internode; glabrous on surface; outer margin hairy. Ligule an eciliate membrane; 1.5 mm long; truncate. Leaf-blades 2–6 cm long; 2 mm wide. Leaf-blade surface glabrous, or puberulous; hairy abaxially. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle.

Panicle open; oblong, or ovate; nodding; 5–10 cm long. Primary panicle branches 2 -nate; 3–6 cm long. Panicle axis scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 3–4 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–11 mm long; 3 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 3 mm long; villous. Floret callus pubescent.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma; shiny. Lower glume lanceolate; 5–7 mm long; 0.8–0.9 length of upper glume; membranous; yellow and purple; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 6–8 mm long; 0.6–0.9 length of adjacent fertile lemma; membranous; yellow and purple; 1-keeled; 3 -veined. Upper glume primary vein scabrous. Upper glume apex acuminate.

FLORETS Fertile lemma lanceolate; 9 mm long; chartaceous; mid-green and purple; tipped with last colour; without keel; 5 -veined. Lemma surface scaberulous. Lemma apex dentate; 2 -fid; with lobes 1.5 mm long; setaceously attenuate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5–0.6 way up back of lemma; geniculate; 12–13 mm long overall; with twisted column. Palea keels ciliolate. Palea apex dentate; 2 -fid. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3; 2 mm long. Ovary pubescent on apex.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-temperate: China.

NOTES Aveneae. Hackel 1996.

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