Arthrostylidium virolinense

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms scandent; 200–300 cm long; 1–3 mm diam.; woody. Culm-internodes terete; solid; 7–21 cm long; papillose; distally glabrous. 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, or 2 branches dominant; thinner than stem. Culm-sheaths persistent; 2–4 cm long; 4 times as long as wide; hispid; ciliate on shoulders; shoulders with curved hairs; shoulders with 1 mm long hairs. Culm-sheath ligule 0.2 mm high; ciliolate. Culm-sheath blade lanceolate; demarcated but persistent; erect; 0.9–2.1 cm long; 1–2 mm wide; hispid. Leaves 8–12 per branch. Leaf-sheaths striately veined; hispid; outer margin hairy. Leaf-sheath oral hairs setose; curly; 3–5 mm long. Ligule a ciliolate membrane; 0.1–0.2 mm long. Collar with external ligule. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.08–0.1 cm long; petiole pubescent. Leaf-blades lanceolate; 1–4.5 cm long; 2–4.5 mm wide; mid-green and light green; discolorous with last colour beneath. Leaf-blade surface glabrous. Leaf-blade margins scabrous. Leaf-blade apex acute.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 3–4 cm long; bearing few fertile spikelets; bearing 1–4 fertile spikelets on each. Rhachis pilose on surface. Spikelet packing broadside to rhachis. Rhachis internodes 5–7 mm long.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 10–16 mm long; 1.5–4 mm wide; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5–2 mm long; pilose.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 1.5–2.5 mm long; chartaceous; without keels; 3 -veined. Lower glume surface hispid. Lower glume apex obtuse. Upper glume ovate; 2.5–3 mm long; without keels; 5 -veined. Upper glume surface hispid. Upper glume apex obtuse.

FLORETS Fertile lemma ovate; 4–4.5 mm long; 2–2.5 mm wide; chartaceous; purple; without keel; 5–6 -veined. Lemma lateral veins with cross-veins. Lemma surface rugulose; without grooves; glabrous, or hispidulous. Lemma margins ciliolate; hairy above. Lemma hairs 4–4.5 mm long. Lemma apex acute. Palea keels eciliate. Palea apex pubescent. Apical sterile florets 1 in number; lanceolate.

FLOWER Lodicules 3; 1–1.5 mm long; veinless. Anthers 3; 2.5–3 mm long; pallid, or yellow. 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.