Ixophorus unisetus

HABIT Perennial; caespitose. Basal innovations flabellate. Culms 50–140 cm long. Ligule an eciliate membrane; 1–2.5 mm long. Leaf-blades 25–75 cm long; 10–25 mm wide.

INFLORESCENCE Inflorescence composed of racemes.

Racemes numerous; borne along a central axis; unilateral; 2–8 cm long. Central inflorescence axis 10–25 cm long. Rhachis angular; terminating in a barren extension; extension bristle-like. Spikelet packing abaxial; regular; 2 -rowed.

Spikelets subtended by an involucre. Fertile spikelets sessile; 1 in the cluster. Involucre composed of bristles; 5–10 mm long. Involucral bristles persistent; few; 1 per spikelet; flexible; viscid.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; 3.5–4.7 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.7–1.5 mm long; 0.2–0.3 length of spikelet; herbaceous; without keels; 3 -veined. Lower glume apex acute. Upper glume ovate; 3.5–4.7 mm long; 1.75 length of adjacent fertile lemma; herbaceous; without keels; 9–11 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; cartilaginous; 5 -veined; acute. Palea of lower sterile floret becoming indurate on flanks at maturity (and orbicular); winged on keels. Fertile lemma elliptic; 2–3 mm long; indurate; without keel. Lemma surface papillose. Lemma margins involute. Lemma apex apiculate. Palea indurate.

DISTRIBUTION Pacific: north-central. North America: Mexico. South America: Mesoamericana, Caribbean, northern South America, and Brazil.

NOTES Paniceae. Pohl.

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