GrassBase - The Online World Grass Flora


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

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

Arthrostylidium urbanii

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms scandent; slender; 500–700 cm long; woody. Culm-internodes terete; with small lumen; smooth; distally glabrous. Lateral branches fastigiate. Branch complement many; in a clump; subtended by a bare patch above the node; with subequal branches. Leaf-sheaths mostly shorter than adjacent culm internode; puberulous. Leaf-sheath oral hairs scanty; curly and deciduous; 3–5 mm long; pale. Ligule an eciliate membrane. Leaf-blade base with a brief petiole-like connection to sheath; petiole pubescent. Leaf-blades spreading, or reflexed; deciduous at the ligule; linear, or lanceolate; 5–13 cm long; 3–5 mm wide; stiff. Leaf-blade surface puberulous; hairy abaxially, or on both sides. Leaf-blade margins scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; straight; bilateral; 5–15 cm long; bearing 10–15 fertile spikelets on each. Rhachis puberulous on surface. Spikelet packing contiguous. Rhachis internodes 2–3 mm long.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 15 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes several; 3 empty glumes; persistent; similar; shorter than spikelet. Lower glume ovate; chartaceous; without keels. Lower glume surface puberulous. Lower glume apex obtuse. Upper glume elliptic; 2.5 mm long. Upper glume surface puberulous. Upper glume apex obtuse.

FLORETS Fertile lemma lanceolate, or ovate; 4.5–5 mm long; chartaceous; without keel; 5–7 -veined. Lemma lateral veins prominent. Lemma surface puberulous. Lemma apex acute; mucronate. Palea 1 length of lemma. Palea keels ciliolate; adorned above. 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. Pilger 1997.

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