GrassBase - The Online World Grass Flora


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

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

Bambusa laxa

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms arching; 500–600 cm long; 20–40 mm diam.; woody; without nodal roots. Culm-internodes terete; hollow; 20–35 cm long; distally pruinose and pubescent. Lateral branches dendroid. Bud complement 1. Culm-sheaths green; hispid; with dark brown hairs; auriculate; with 8 mm high auricles; setose on shoulders; shoulders with 10–12 mm long hairs. Culm-sheath ligule 2 mm high; ciliate. Culm-sheath blade lanceolate, or triangular; erect; pubescent. Leaves cauline. Leaf-sheath oral hairs ciliate; 2–3 mm long. Ligule an eciliate membrane, or a ciliolate membrane; 0.5 mm long. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades lanceolate; 6–15 cm long; 10–15 mm wide. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

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

FERTILE SPIKELETS Spikelets comprising 6–7 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 20–26 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; 2–3 mm long; pubescent; hairy at tip.

GLUMES Glumes several; comprising 2–3 gemmiferous bracts; 0–1 empty glumes.

FLORETS Fertile lemma ovate; 10–15 mm long; without keel; 28 -veined. Lemma inner surface pubescent (above). Lemma margins ciliolate. Lemma apex acute. Palea 11–14 -veined. Palea keels ciliolate; adorned above; with hairs 0.4–0.8 mm long. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; 2 mm long; membranous; ciliate. Anthers 6; 5–6 mm long; purple; anther tip penicillate. Filaments united in a tube. Stigmas 1; pubescent. Ovary umbonate; pubescent on apex.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Bambuseae. Wong 1996.

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