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 guatemalense

HABIT Perennial. Culms 75 cm long. Culm-internodes scaberulous; distally pilose; with tubercle-based hairs. Lateral branches ample. Leaf-sheaths glabrous on surface, or pilose; with tubercle-based hairs. Ligule an eciliate membrane; 0.2 mm long. Collar pubescent. Leaf-blades lanceolate; 7–12 cm long; 4–10 mm wide. Leaf-blade surface scaberulous; pilose; with tubercle-based hairs. Leaf-blade margins cartilaginous; scabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; lanceolate; 10 cm long; contracted about primary branches. Primary panicle branches appressed, or ascending; 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; dorsally compressed; 2.2–2.4 mm long; falling entire.

GLUMES Glumes reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.5–1 mm long; 0.25–0.33 length of spikelet; membranous; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume ovate; 1 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 5 -veined; acute. Fertile lemma elliptic; dorsally compressed; 2 mm long; indurate; shiny; without keel. Lemma margins involute. Lemma apex pubescent. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Paniceae. Swallen 1995.

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