Zeugites americanus

HABIT Perennial. Rhizomes absent, or elongated. Culms rambling; 100–200 cm long. Lateral branches ample. Leaf-sheaths glabrous on surface, or hirsute. Ligule an eciliate membrane; 1–2 mm long; glabrous on abaxial surface, or pilose on abaxial surface. Leaf-blade base broadly rounded; with a false petiole; petiole 0.7–1 cm long. Leaf-blades lanceolate; 2.5–4 cm long; 7–17 mm wide. Leaf-blade venation with distinct cross veins. Leaf-blade surface glabrous, or pilose; sparsely hairy; hairy adaxially. Leaf-blade apex acute.

INFLORESCENCE Inflorescence a panicle. Peduncle 7–15 cm long; glabrous.

Panicle open; oblong, or pyramidal; 7–10 cm long. Primary panicle branches spreading.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 6–8 mm long; falling entire; readily shedding apical florets (as a group).

GLUMES Glumes dissimilar; with lower wider than upper; shorter than spikelet; thinner than fertile lemma. Lower glume obovate; 2–3 mm long; 1 length of upper glume; membranous; 1-keeled; 5–7 -veined. Lower glume lateral veins with cross-veins. Lower glume apex truncate. Upper glume oblong; 2–3 mm long; 0.66 length of adjacent fertile lemma; membranous; 1-keeled; 3–5 -veined. Upper glume lateral veins with cross-veins. Upper glume apex obtuse.

FLORETS Fertile florets female. Fertile lemma oblong; 3.5–4.5 mm long; cartilaginous; keeled; 9–11 -veined. Lemma apex erose; truncate. Palea 1.1 length of lemma. Apical sterile florets 1–2 in number; male; ovate; 3–3.5 mm long. Apical sterile lemmas acute.

FLOWER Anthers 3; 1.5–2 mm long.

DISTRIBUTION North America: Mexico. South America: Mesoamericana, Caribbean, northern South America, and western South America.

NOTES Centotheceae. Fl Costa Rica 1994.

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