Panicum petersonii

HABIT Perennial. Butt sheaths coriaceous. Culms erect; 200 cm long; firm. Culm-internodes distally glabrous. Culm-nodes flush with internodes. Lateral branches sparse. Leaves without demarcation between sheath and blade. Leaf-sheaths glabrous on surface. Ligule a ciliate membrane. Leaf-blades erect; 40–100 cm long; 1–3 mm wide; coriaceous; stiff. Leaf-blade midrib widened. Leaf-blade margins scabrous. Leaf-blade apex attenuate; filiform.

INFLORESCENCE Inflorescence a panicle; terminal and axillary.

Panicle open; ovate; dense; 15–25 cm long. Primary panicle branches ascending; closely spaced; bearing spikelets almost to the base. Panicle axis scabrous.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; obtuse; 2.3 mm long; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.5 length of spikelet; membranous; without keels; 3–5 -veined. Lower glume apex acute. Upper glume elliptic; 0.9 length of spikelet; membranous; without keels; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; acute. Palea of lower sterile floret scabrous; adorned on keels. Fertile lemma elliptic; dorsally compressed; 2 mm long; indurate; pallid; without keel. Lemma margins involute. Lemma apex acute. Palea involute; indurate.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: Caribbean.

NOTES Paniceae. Man Gr US 1994.

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