GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Arthrostylidium ekmanii

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms scandent; slender; drooping at the tip; 2 mm diam.; woody. Culm-internodes terete; with small lumen; 25 cm long; retrorsely scabrous; distally glabrous. Lateral branches fastigiate. Branch complement many; in a clump; subtended by a bare patch above the node; with subequal branches. Leaf-sheaths striately veined; glabrous on surface. Leaf-sheath oral hairs setose; 5–7 mm long. Ligule an eciliate membrane. Leaf-blade base with a brief petiole-like connection to sheath; petiole 0.1 cm long. Leaf-blades deciduous at the ligule; lanceolate; 3–6 cm long; 4–8 mm wide. Leaf-blade surface glabrous. Leaf-blade apex hairy.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; straight; bilateral; 0–5 cm long; bearing 1–3 fertile spikelets on each. Spikelet packing lax.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 4–5 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 30–50 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes zig-zag; eventually visible between lemmas; glabrous.

GLUMES Glumes several; 3 empty glumes; persistent; similar; shorter than spikelet. Lower glume ovate; 3–7 mm long; chartaceous; without keels. Lower glume apex acute. Upper glume lanceolate; 5–9 mm long. Upper glume apex acute.

FLORETS Fertile lemma lanceolate, or ovate; widest at 0.33 of its length from base; 9–12 mm long; 1.5 mm wide; chartaceous; light brown; without keel. Lemma apex obtuse; mucronate. Palea bowed outwards; 1 length of lemma. Palea surface puberulous; hairy on back. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3. Anthers 3. Stigmas 2. Ovary umbonate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Caribbean.

NOTES Bambuseae. Man Gr WI 1997.

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