Guadua macrostachya

HABIT Perennial; caespitose; clumped densely. Rhizomes short; pachymorph. Culms 800–1800 cm long; 40–70 mm diam.; woody; with root thorns from the nodes. Culm-internodes semiterete. Lateral branches dendroid. Bud complement 1. Leaves 7–11 per branch. Leaf-sheaths glabrous on surface; outer margin glabrous, or hairy. Leaf-sheath oral hairs lacking. Ligule an eciliate membrane; 1 mm long. Collar with external ligule. Leaf-blade base cuneate; with a brief petiole-like connection to sheath; petiole 0.3–0.5 cm long; petiole pilose. Leaf-blades linear, or lanceolate; 15–21 cm long; 8–22 mm wide; mid-green. Leaf-blade venation with obscure cross veins, or with distinct cross veins. Leaf-blade surface glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Synflorescence bractiferous; scanty; axis 0–5 cm long; lax; with glumaceous subtending bracts; with axillary buds at base of spikelet; prophyllate below lateral spikelets.

Spikelets appressed, or ascending. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 5–7 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 35–65 mm long; 3.5–6 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes obscured by lemmas.

FLORETS Fertile lemma ovate; 12–15 mm long; coriaceous; dull; without keel; 15–20 -veined. Lemma lateral veins prominent. Lemma surface pubescent. Lemma margins ciliolate. Lemma apex acuminate. Palea 10 mm long. Palea keels winged; conspicuously winged. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; 3–4 mm long; veined. Anthers 6; 5–6 mm long. Stigmas 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: northern South America.

NOTES Bambuseae. Fl Guiana 1995.

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