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.

Panicum petrense

HABIT Annual; caespitose; clumped densely. Culms erect; slender; 25–30 cm long. Lateral branches ample; erect. Leaf-sheaths mostly shorter than adjacent culm internode, or subequal to internodes. Ligule an eciliate membrane; 0.3 mm long. Leaf-blades erect, or ascending; 1.5–3 cm long; 1.5–3 mm wide; glaucous. Leaf-blade surface glabrous; hairless throughout, or except near base.

INFLORESCENCE Inflorescence a panicle.

Panicle open; ovate; 1.5–3 cm long. Primary panicle branches ascending, or spreading; 1 -nate. Panicle branches scaberulous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; 1.2–1.3 mm long; falling entire.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.6–0.7 mm long; 0.5 length of spikelet; membranous. Lower glume lateral veins absent. Lower glume apex obtuse, or acute. Upper glume ovate; 0.66–0.75 length of spikelet; membranous; without keels. Upper glume surface pubescent.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; pubescent. Fertile lemma ovate; dorsally compressed; 0.8 mm long; indurate; pallid; without keel. Lemma surface striate. Lemma margins involute. Palea involute; indurate.

DISTRIBUTION South America: northern South America.

NOTES Paniceae. Swallen 2002.

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