Gigantochloa rostrata

HABIT Perennial; caespitose; clumped loosely. Rhizomes short; pachymorph. Culms erect; drooping at the tip; 400–800 cm long; 20–35 mm diam.; woody. Culm-internodes terete; 15–30 cm long; dark green and yellow; striped; distally hispid. Lateral branches dendroid. Buds or branches absent from lower quarter of culm. Branch complement several; with 1 branch dominant. Culm-sheaths deciduous; 5–10 cm long; 2 times as long as wide; green and yellow; striped; hispid; with appressed hairs; auriculate; with 0.5–1 mm high auricles; glabrous on shoulders. Culm-sheath ligule dentate. Culm-sheath blade lanceolate; spreading, or reflexed; 8 cm long; 5 mm wide. Leaf-sheath oral hairs lacking. Leaf-sheath auricles absent. Ligule an eciliate membrane; 3–8 mm long. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.4 cm long. Leaf-blades lanceolate; 10–21 cm long; 20–30 mm wide. Leaf-blade surface pubescent.

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; leafless between clusters.

Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 3 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 26–31 mm long; 2–3 mm wide; breaking up at maturity; disarticulating above glumes but not between florets. Rhachilla internodes suppressed between florets.

GLUMES Glumes several; 3 empty glumes; persistent; similar; shorter than spikelet. Upper glume ovate; 6–11 mm long. Upper glume margins ciliate. Upper glume hairs dark brown. Upper glume apex acuminate.

FLORETS Fertile florets increasing in size upwards. Fertile lemma lanceolate; 15–30 mm long; chartaceous; without keel. Lemma surface pubescent. Lemma margins ciliate; hairy above. Lemma hairs dark brown. Lemma apex rostrate. Palea 10–22 mm long; 11 -veined; 2-keeled. Palea apex dentate; 1 -fid. Apical sterile florets 1 in number; barren; lanceolate.

FLOWER Lodicules absent. Anthers 6; 6–10 mm long; red; anther tip with extended connective and pubescent. Filaments united in a tube; united for 1 of their length. Stigmas 1. Ovary umbonate; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; linear; sulcate on hilar side; 10–14 mm long; light brown; hairy at apex.

DISTRIBUTION Asia-tropical: Malesia.

NOTES Bambuseae. Widjaja 1996.

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