Gigantochloa macrostachya

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms erect; 1000–1600 cm long; 6–10 mm diam.; woody. Culm-internodes terete; hollow; 40–80 cm long; dark green, or glaucous. Culm-nodes pubescent. Lateral branches dendroid. Culm-sheaths 12–20 cm long; 0.5 times as long as wide; hispid; with appressed hairs; with black hairs; hairy on margins; truncate at apex; auriculate; ciliate on shoulders. Culm-sheath ligule entire, or dentate. Culm-sheath blade ovate; narrower than sheath; pubescent; acute. Leaf-sheaths keeled; pubescent. Leaf-sheath oral hairs scanty; deciduous. Leaf-sheath auricles falcate. Ligule an eciliate membrane. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades lanceolate; 15–40 cm long; 12–15 mm wide. Leaf-blade midrib evident. Leaf-blade venation with 10–26 secondary veins. Leaf-blade surface puberulous; hairy abaxially. Leaf-blade margins scabrous. Leaf-blade apex antrorsely scabrous.

INFLORESCENCE Synflorescence bractiferous; clustered at the nodes; in stellate clusters; 5–7 cm long; with glumaceous subtending bracts; with axillary buds at base of spikelet; prophyllate below lateral spikelets.

Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 25–50 mm long; 2.5 mm wide; 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. Upper glume ovate; 7.5–15 mm long. Upper glume surface hispid. Upper glume margins ciliate. Upper glume hairs black. Upper glume mucronate.

FLORETS Fertile florets increasing in size upwards. Fertile lemma lanceolate; 12–25 mm long; chartaceous; without keel. Lemma apex acute; mucronate. Palea linear; 1 length of lemma; 2-keeled. Palea keels ciliate. Apical sterile florets 1 in number; barren; rudimentary.

FLOWER Lodicules absent. Anthers 6; 10–12 mm long; purple; anther tip apiculate. Filaments united in a tube. Stigmas 1; pubescent. Ovary umbonate; pubescent on apex.

FRUIT Caryopsis with adherent pericarp; linear; hairy at apex.

DISTRIBUTION Asia-tropical: India and Indo-China.

NOTES Bambuseae. Gamble 1995.

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