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.

 

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:

• Brazil
• Guyanas

Sources:
GrassBase - The Online World Grass Flora
INBAR (International Network for Bamboo and Rattan)