Gigantochloa thoi

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms erect; 1000–1600 cm long; 90–120 mm diam.; woody. Culm-internodes terete; hollow; 35–45 cm long; glaucous; distally pruinose and hispid. Lateral branches dendroid. Culm-sheaths deciduous but leaving a persistent girdle; green; hispid; with dark brown hairs; auriculate; with 6–10 mm high auricles; setose on shoulders; shoulders with 10–18 mm long hairs. Culm-sheath ligule 7–22 mm high; fimbriate. Culm-sheath blade lanceolate; spreading, or reflexed. Leaf-sheath oral hairs ciliate; 4 mm long. Leaf-sheath auricles falcate; 0.5–1 mm long. Ligule an eciliate membrane; 0.5–1.5 mm long; erose. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.3–0.5 cm long. Leaf-blades lanceolate; 8–32 cm long; 20–60 mm wide. Leaf-blade surface pubescent; hairy abaxially.

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

Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 4–5 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 9–15 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Rhachilla internodes suppressed between florets.

GLUMES Glumes several; 2–3 empty glumes; persistent; similar; shorter than spikelet.

FLORETS Fertile florets increasing in size upwards. Fertile lemma ovate; 8–11 mm long; chartaceous; without keel. Lemma surface puberulous. Lemma margins ciliolate. Lemma apex cuspidate. Palea 1 length of lemma; 6–10 -veined; 2-keeled. Palea keels ciliolate. Palea surface puberulous; hairy on back. Apical sterile florets 1 in number; barren; lanceolate.

FLOWER Lodicules absent. Anthers 6; 5.5–6 mm long; anther tip penicillate. Filaments united in a tube. Stigmas 1; pubescent. Ovary umbonate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Bambuseae. Wong 1996.

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