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.

Panicum arundinariae

HABIT Perennial; caespitose. Culms 50–80 cm long; 1–1.5 mm diam.; without nodal roots, or rooting from lower nodes. Culm-internodes distally glabrous. Culm-nodes bearded. Lateral branches ample. Leaf-sheaths glabrous on surface; outer margin hairy. Leaf-sheath oral hairs bearded. Ligule a ciliolate membrane; 0.3–0.8 mm long. Collar bearded. Leaf-blade base broadly rounded. Leaf-blades lanceolate; 4–11 cm long; 4–9 mm wide. Leaf-blade surface glabrous, or puberulous; sparsely hairy.

INFLORESCENCE Inflorescence a panicle. Peduncle 4–17 cm long.

Panicle open; ovate; 2–6 cm long; contracted about primary branches. Primary panicle branches 3–5 in number; 0.5–1.5 cm long; bearing spikelets almost to the base.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or obovate; dorsally compressed; obtuse; 1.7–1.9 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume oblate; 0.5–0.6 mm long; 0.33 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume ovate; 1.7–1.9 mm long; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex obtuse.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1.7–1.9 mm long; 1 length of spikelet; membranous; 5 -veined; obtuse. Fertile lemma elliptic; dorsally compressed; 1.5–1.6 mm long; indurate; shiny; without keel. Lemma surface striate; pubescent. Lemma margins involute. Lemma apex obtuse. Palea involute; indurate. Palea surface pubescent; hairy on back.

FLOWER Anthers 3; 0.7 mm long; orange.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.1 mm long; yellow.

DISTRIBUTION North America: Mexico. South America: Mesoamericana and western South America.

NOTES Paniceae. Fl Costa Rica 1994.

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