Arthrostylidium venezuelae

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms rambling, or scandent; slender; 300–800 cm long; 10–30 mm diam.; woody. Culm-internodes terete; with small lumen, or solid; scaberulous; distally glabrous, or pubescent; with reflexed hairs. Culm-nodes pubescent. Lateral branches dendroid. Bud complement 1. Branch complement in a clump; subtended by a bare patch above the node; with 1 branch dominant; thinner than stem. Culm-sheaths glabrous; without auricles. Leaf-sheaths glabrous on surface; outer margin hairy. Leaf-sheath oral hairs setose; 5–9 mm long; dark. Ligule a ciliolate membrane; 0.2 mm long. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.1–0.35 cm long; petiole pubescent. Leaf-blades deciduous at the ligule; ovate; 5–14 cm long; 10–15 mm wide; dark green. Leaf-blade surface pilose; sparsely hairy; hairy abaxially.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; flexuous; bilateral; 5–8 cm long. Rhachis semiterete. Spikelet packing broadside to rhachis; distant.

Spikelets ascending; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 4–8 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 10–20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes flattened; clavate; 4.5–7 mm long; eventually visible between lemmas; sparsely hairy; hairy at tip.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume elliptic; 3–4 mm long; 0.7–0.8 length of upper glume; chartaceous; without keels; 4 -veined. Lower glume apex acute. Upper glume elliptic; 4–5 mm long; 0.66 length of adjacent fertile lemma; without keels; 7 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea; persisting on inflorescence. Lemma of lower sterile floret similar to fertile lemma. Fertile lemma ovate; 6–7.5 mm long; chartaceous; without keel; 9 -veined. Lemma surface pubescent. Lemma apex obtuse. Palea 1 length of lemma. Palea keels ciliolate; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3. Anthers 3; 3.2–3.5 mm long; yellow. Stigmas 2. Ovary umbonate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Mesoamericana, northern South America, and western South America.

NOTES Bambuseae. Fl Costaric 1993.

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