Panicum tamaulipense

HABIT Perennial; caespitose. Culms erect; 50–1550 cm long. Culm-internodes distally glabrous, or hispid; with tubercle-based hairs. Leaf-sheaths glabrous on surface, or hispid; with tubercle-based hairs. Ligule a fringe of hairs; 0.8 mm long. Leaf-blades erect, or spreading; flat, or conduplicate; 10–50 cm long; 3–8 mm wide; glaucous. Leaf-blade surface glabrous.

INFLORESCENCE Inflorescence a panicle.

Panicle open; pyramidal; 15–40 cm long; with spikelets clustered towards branch tips. Primary panicle branches ascending; 1–3 -nate. Panicle branches stiff.

Spikelets appressed; solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acuminate; 1.8–2.2 mm long; 0.8 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.5 length of spikelet; membranous; without keels; 5 -veined. Lower glume apex acute. Upper glume ovate; 1 length of spikelet; membranous; without keels; 7–9 -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; 7–9 -veined; acute. Fertile lemma elliptic; dorsally compressed; 1.5–1.7 mm long; 0.6–0.8 mm wide; indurate; dark brown; shiny; without keel. Lemma margins involute. Palea involute; indurate.

DISTRIBUTION North America: Mexico.

NOTES Paniceae. Waller & NMorden 2004.

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