Thrasya robusta

HABIT Perennial; caespitose. Culms erect; robust; 100–200 cm long. Culm-nodes bearded. Leaf-sheaths keeled; pubescent; outer margin hairy. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades linear, or lanceolate; flat, or conduplicate; 15–30 cm long; 4–15 mm wide. Leaf-blade surface scaberulous; rough abaxially; puberulous; hairy adaxially. Leaf-blade margins tuberculate-ciliate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1(–2); single, or paired; arcuate; unilateral; 8–30 cm long. Rhachis broadly winged; folded longitudinally to embrace spikelets; 2 mm wide; glabrous on surface; glabrous on margins; terminating in a barren extension; extension flattened. Spikelet packing alternately adaxial and abaxial; regular; 1 -rowed.

Spikelets pectinate; in pairs. Fertile spikelets sessile and pedicelled; 2 in the cluster. Pedicels fused to internode; united wholly.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic, or oblong; dorsally compressed; 3.2–4 mm long; 1.2 mm wide; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.4(–2) mm long; 0.1(–0.6) length of spikelet; hyaline; without keels; 0(–1) -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 3.2–4 mm long; 1 length of spikelet; chartaceous; without keels; 5 -veined. Upper glume surface pilose. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret elliptic, or oblong; 1 length of spikelet; coriaceous; sulcate and readily splitting into two halves; ciliolate on margins; acute. Palea of lower sterile floret becoming indurate on flanks at maturity. Fertile lemma elliptic; 3.1 mm long; coriaceous; without keel. Lemma surface papillose and striate. Lemma margins involute. Lemma apex acute. Palea coriaceous.

FLOWER Lodicules 2; fleshy; truncate. Anthers 3.

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

NOTES Paniceae. Burman 1993.

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