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Descriptions

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

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

Vietnamosasa pusilla

HABIT Perennial. Rhizomes elongated; leptomorph; scaly. Culms 50–150 cm long; 3–8 mm diam.; woody. Culm-internodes terete; with small lumen, or solid; light green; distally glabrous. Lateral branches dendroid. Branch complement many. Culm-sheaths 3–5 cm long. Culm-sheath blade triangular; deciduous; erect; glabrous on surface. Leaf-sheaths glabrous on surface; outer margin hairy. Leaf-sheath oral hairs setose. Ligule an eciliate membrane; pubescent on abaxial surface. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.07 cm long. Leaf-blades deciduous at the ligule; lanceolate; 8–14 cm long; 8–10 mm wide; coriaceous; stiff; light green. Leaf-blade venation with 6–8 secondary veins; with distinct cross veins. Leaf-blade surface pubescent; hairy on both sides. Leaf-blade margins scaberulous. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence on a separate leafless culm. Inflorescence a panicle; subtended by a spatheole; embraced at base by subtending leaf. Peduncle pubescent above.

Panicle open; lanceolate; bearing few spikelets. Panicle axis pubescent.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 7–9 fertile florets; with diminished florets at the apex. Spikelets linear, or oblong; laterally compressed; 30–40 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 3 mm long; eventually visible between lemmas.

GLUMES Glumes several; 0–2 empty glumes; persistent; similar; shorter than spikelet. Lower glume ovate; 7.5–10 mm long; chartaceous; without keels. Lower glume apex acute. Upper glume ovate; 7.5–10 mm long; chartaceous; without keels. Upper glume apex acute.

FLORETS Fertile lemma ovate; 8–14 mm long; chartaceous; without keel; 17–23 -veined. Lemma apex obtuse. Palea 7 -veined. Palea keels ciliate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; ciliate. Anthers 6; 6–7 mm long; purple. Stigmas 3.

FRUIT Caryopsis with adherent pericarp; apex unappendaged.

DISTRIBUTION Asia-tropical: Indo-China.

NOTES Bambuseae. Lecomte 1996.

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