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.

Bambusa polymorpha

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms erect; 1500–2500 cm long; 75–150 mm diam.; woody; with aerial roots from the nodes. Culm-internodes terete; 40–60 cm long; grey; distally pruinose. Culm-nodes swollen. Lateral branches dendroid. Culm-sheaths 15–18 cm long; 0.5 times as long as wide; pubescent; with appressed hairs; with white hairs; truncate at apex; auriculate; setose on shoulders. Culm-sheath blade triangular; cordate; 7.5 cm long; pubescent. Leaves cauline. Leaf-sheaths keeled; striately veined; pubescent. Leaf-sheath oral hairs scanty; deciduous. Leaf-sheath auricles falcate. Ligule an eciliate membrane. Collar with external ligule. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.1 cm long. Leaf-blades persistent, or deciduous at the ligule; lanceolate; 7–17 cm long; 7–12 mm wide. Leaf-blade venation with 8–12 secondary veins. Leaf-blade surface scaberulous; rough adaxially; pubescent; hairy on both sides. Leaf-blade margins scaberulous. Leaf-blade apex acuminate; antrorsely scabrous.

INFLORESCENCE Synflorescence bractiferous; clustered at the nodes; in untidy tufts; with glumaceous subtending bracts; with axillary buds at base of spikelet; prophyllate below lateral spikelets.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets lanceolate; subterete; 10–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; flattened; glabrous.

GLUMES Glumes several; 1–3 empty glumes. Upper glume ovate. Upper glume mucronate.

FLORETS Fertile lemma ovate; 5–6 mm long; without keel. Lemma apex acute; mucronate. Palea keels eciliate. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; membranous; veined; ciliate. Anthers 6; purple; anther tip smooth, or apiculate. Stigmas 3; pubescent. Ovary umbonate; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; ovoid; 5 mm long; hairy at apex.

DISTRIBUTION Asia-temperate: China. Asia-tropical: India and Indo-China. Pacific: northwestern.

NOTES Bambuseae. Gamble 1995.

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