Pseudostachyum polymorphum

HABIT Perennial; culms solitary. Rhizomes elongated; pachymorph. Culms erect, or leaning; 1500–2000 cm long; 30–35 mm diam.; woody. Culm-internodes terete; hollow; 20–23 cm long; dark green, or glaucous. Lateral branches dendroid. Culm-sheaths pubescent; with appressed hairs; with dark brown hairs; truncate at apex; auriculate; ciliate on shoulders. Culm-sheath ligule dentate. Culm-sheath blade triangular; as wide as sheath at base; acuminate. Leaf-sheaths puberulous. Ligule an eciliate membrane. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.7–1.3 cm long. Leaf-blades lanceolate, or oblong; 10–20 cm long; 25–60 mm wide. Leaf-blade venation with 14–22 secondary veins; with distinct cross veins. Leaf-blade surface smooth. Leaf-blade apex attenuate.

INFLORESCENCE Synflorescence bractiferous; paniculate; lax; with glumaceous subtending bracts; with axillary buds at base of spikelet; prophyllate below lateral spikelets.

Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with a barren rhachilla extension. Spikelets ovate; laterally compressed; 5 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes several; 3–5 empty glumes; persistent; shorter than spikelet. Upper glume ovate; chartaceous; without keels; 7 -veined. Upper glume apex acute; mucronate.

FLORETS Fertile lemma ovate; 5 mm long; chartaceous; without keel. Lemma margins ciliate. Lemma apex acute. Palea tightly convolute around flower; chartaceous. Palea keels ciliate.

FLOWER Lodicules 3, or several (3–5); ciliate. Anthers 6; anther tip apiculate. Stigmas 2; pubescent. Ovary with a steeple-like appendage; glabrous.

FRUIT Caryopsis with free brittle pericarp; orbicular.

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

NOTES Bambuseae. Gamble 1996.

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