Arthrostylidium chiribiquetense

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms scandent; 300–500 cm long; 3–6 mm diam.; woody. Culm-internodes terete; hollow (pith filled); 28–52 cm long; distally hispid; with reflexed hairs. Lateral branches dendroid; intravaginal. Bud complement 1. Branch complement several; in a clump; subtended by a bare patch above the node; with 1 branch dominant; thinner than stem. Culm-sheaths persistent; 3.5–5 cm long; 3 times as long as wide; glabrous, or puberulous; ciliate on shoulders; shoulders with curved hairs; shoulders with 2 mm long hairs. Culm-sheath ligule 0.2 mm high. Culm-sheath blade ovate; demarcated but persistent; erect; 1–4 cm long; 9–20 mm wide; glabrous on surface and with ciliate margins. Leaves 9–14 per branch. Leaf-sheaths 2.5–4 cm long; mostly shorter than adjacent culm internode, or subequal to internodes; striately veined; glabrous on surface. Leaf-sheath oral hairs setose; curly; 5–10 mm long; dark. Ligule a ciliolate membrane; 0.8–1 mm long; pubescent on abaxial surface. Collar with external ligule. Leaf-blade base truncate; with a brief petiole-like connection to sheath; petiole 0.2–0.5 cm long. Leaf-blades ovate; 6–18.5 cm long; 20–50 mm wide. Leaf-blade midrib indistinct. Leaf-blade venation with distinct cross veins. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; straight; bilateral; 8–17 cm long; bearing 10–18 fertile spikelets on each. Rhachis glabrous on surface, or pilose on surface. Spikelet packing broadside to rhachis; lax. Rhachis internodes 5–10 mm long.

Spikelets spreading; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 5–17 mm long; 0.6–0.8 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 6.5–7 mm long.

GLUMES Glumes two, or several; comprising 0–2 gemmiferous bracts; 1–2 empty glumes; persistent; similar; shorter than spikelet. Lower glume ovate; 3–4 mm long; chartaceous; without keels; 5–7 -veined. Lower glume lateral veins prominent. Lower glume surface pubescent. Lower glume margins ciliolate. Lower glume apex acute. Upper glume ovate; 4.3–5.5 mm long; without keels; 5–7 -veined. Upper glume primary vein conspicuous. Upper glume surface pubescent. Upper glume margins ciliolate. Upper glume apex acute.

FLORETS Fertile lemma oblong; 5.5–8.5 mm long; 2–2.5 mm wide; chartaceous; without keel; 7–9 -veined. Lemma surface rugulose; without grooves; pubescent. Lemma margins ciliolate; hairy above. Lemma apex acute; mucronate. Palea 6.5–8.1 mm long. Palea apex ciliate. Apical sterile florets 1 in number; rudimentary.

FLOWER Lodicules 3; 1.5 mm long; veined; ciliate. Anthers 3. Stigmas 2.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: western South America.

NOTES Bambuseae. Lord & Clarke 2001.

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