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Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Helictotrichon tibeticum

HABIT Perennial. Culms erect; 100–120 cm long. Culm-internodes scaberulous; distally glabrous. Leaf-sheaths smooth, or scaberulous; glabrous on surface. Ligule a ciliolate membrane. Leaf-blades involute; 20–30 cm long; 2–3 mm wide. Leaf-blade surface scabrous.

INFLORESCENCE Inflorescence a panicle. Peduncle pubescent above.

Panicle contracted; oblong, or ovate; 3–6 cm long. Panicle axis pubescent. Panicle branches pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 12–15 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes pilose. Floret callus pilose.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 10 mm long; 1 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 10 mm long; 1.2 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Fertile lemma lanceolate; 8 mm long; cartilaginous; without keel; 5–7 -veined. Lemma surface scabrous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 10 mm long overall; with twisted column. Palea 1 length of lemma. Palea surface puberulous; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Anthers 3. Ovary pubescent on apex.

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

DISTRIBUTION Asia-temperate: China.

NOTES Aveneae. Hitchc 2000.

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