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 parcum

HABIT Annual; caespitose. Culms erect; 50–125 cm long; 2–3 mm diam. Culm-internodes distally pilose; with tubercle-based hairs. Culm-nodes constricted; brown; glabrous. Lateral branches lacking. Leaf-sheaths pilose; with tubercle-based hairs. Ligule a ciliate membrane; 1.2–1.3 mm long. Leaf-blades 11–35 cm long; 6–10 mm wide. Leaf-blade surface glabrous, or pilose; with tubercle-based hairs. Leaf-blade apex abruptly acute.

INFLORESCENCE Inflorescence a panicle. Peduncle 5–9 cm long.

Panicle open; ovate; 20–35 cm long; 12 cm wide. Primary panicle branches 1 -nate; 9–18 cm long. Panicle branches glabrous in axils.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acuminate; 4.7–5.1 mm long; falling entire. Rhachilla internodes elongated between glumes. Rhachilla elongation 0.5–0.8 mm long.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 3.1–3.7 mm long; 0.75 length of spikelet; membranous; without keels; 5–7 -veined. Lower glume apex acuminate. Upper glume ovate; 3.9–4.7 mm long; 1 length of spikelet; membranous; without keels; 9 -veined. Upper glume apex acuminate.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 3.8–4.2 mm long; 1 length of spikelet; membranous; 9 -veined; acute. Fertile lemma ovate; dorsally compressed; 2.8–3.2 mm long; indurate; shiny; without keel. Lemma margins involute. Palea involute; indurate.

FLOWER Anthers 3; 1.2–1.4 mm long; purple.

FRUIT Caryopsis ellipsoid; pallid.

DISTRIBUTION North America: Mexico. South America: Mesoamericana.

NOTES Paniceae. Fl Costa Rica 1994.

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