Arthrostylidium merostachyoides

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms arching; 500–1000 cm long; 10–15 mm diam.; woody. Culm-internodes terete; with small lumen; yellow; distally glabrous. Lateral branches dendroid. Branch complement many; in a clump; subtended by a bare patch above the node. Culm-sheaths persistent; glabrous; without auricles. Culm-sheath ligule 0.5 mm high; ciliolate. Culm-sheath blade lanceolate; demarcated but persistent, or deciduous; acuminate. Leaves 4–7 per branch. Leaf-sheaths glabrous on surface; outer margin hairy. Leaf-sheath oral hairs setose; 7–16 mm long. Ligule a ciliolate membrane; 0.5–0.6 mm long. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.15–0.25 cm long; petiole pubescent. Leaf-blades drooping; deciduous at the ligule; lanceolate, or oblong; 4–17 cm long; 10–26 mm wide. Leaf-blade surface glabrous. Leaf-blade margins pubescent; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle contracted; oblong; secund; 2.5–8 cm long. Primary panicle branches indistinct the panicle almost racemose.

Spikelets pectinate; in pairs. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 2–3 fertile florets; with diminished florets at the apex. Spikelets obovate; laterally compressed; 9.5–14 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; shorter than spikelet. Lower glume oblong; 0.1–2.5 mm long; chartaceous; without keels; 1–3 -veined. Lower glume lateral veins absent, or distinct. Lower glume apex acute. Upper glume ovate; 2–3.5 mm long; 0.33–0.66 length of adjacent fertile lemma; 3–5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea, or without significant palea; persisting on inflorescence. Lemma of lower sterile floret similar to fertile lemma; ovate; 3.5–5 mm long; 3–7 -veined; acute. Fertile lemma lanceolate, or ovate; 6.2–8.2 mm long; chartaceous; keeled; 5–7 -veined. Lemma apex acute. Palea 1 length of lemma; 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; membranous; veined; glabrous. Anthers 3; 3.2–4.2 mm long. Stigmas 2. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Mesoamericana.

NOTES Bambuseae. Pohl 1995.

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