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 pubescens

HABIT Perennial; caespitose. Rhizomes short; pachymorph. Culms erect, or geniculately ascending; 1000–1500 cm long; 10–20 mm diam.; woody. Culm-internodes terete; with small lumen; distally hispid. Lateral branches dendroid. Bud complement 1. Branch complement many; in a clump; subtended by a bare patch above the node; with 1 branch dominant; thinner than stem. Culm-sheaths hispid; without auricles. Culm-sheath ligule 2 mm high. Culm-sheath blade lanceolate; 10–23 cm long; hispid; acute. Leaf-sheaths glabrous on surface; outer margin hairy. Leaf-sheath oral hairs woolly; dark. Ligule an eciliate membrane. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades deciduous at the ligule; lanceolate; 6–20 cm long; 4–15 mm wide. Leaf-blade surface glabrous. Leaf-blade margins scaberulous.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; bilateral; 3–14 cm long. Rhachis semiterete. Spikelet packing broadside to rhachis; distant.

Spikelets appressed; solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 4–8 fertile florets; with diminished florets at the apex. Spikelets linear; laterally compressed; 30–40 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes eventually visible between lemmas.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume elliptic; 3–4 mm long; 0.7–0.8 length of upper glume; chartaceous; without keels; 3–5 -veined. Lower glume apex acute. Upper glume elliptic; 4–5 mm long; 0.5 length of adjacent fertile lemma; without keels; 3–5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea; persisting on inflorescence. Lemma of lower sterile floret similar to fertile lemma. Fertile lemma ovate; 8–9 mm long; chartaceous; without keel; 9 -veined. Lemma apex acute. Palea 1 length of lemma. Apical sterile florets resembling fertile though underdeveloped.

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

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Mesoamericana, Caribbean, and northern South America.

NOTES Bambuseae. Pohl.

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