GrassBase - The Online World Grass Flora


W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Thrasya thrasyoides

HABIT Perennial; caespitose. Culms erect; 30–100 cm long. Culm-nodes glabrous, or bearded. Leaf-sheaths keeled; pilose; with tubercle-based hairs; outer margin hairy. Ligule an eciliate membrane; 1.5–3 mm long; truncate. Leaf-blades linear, or lanceolate; 4–15 cm long; 3–6 mm wide. Leaf-blade surface pubescent to pilose; with tubercle-based hairs. Leaf-blade margins glabrous, or tuberculate-ciliate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; arcuate; unilateral; 4.5–12 cm long. Rhachis broadly winged; folded longitudinally to embrace spikelets; 2.5 mm wide; glabrous on surface, or pubescent on surface; tuberculate on margins; ciliate on margins; terminating in a barren extension; extension flattened. Rhachis hairs white, or yellow. 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; 3–3.5 mm long; 0.9 mm wide; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.3 mm long; 0.1 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 1.5–2 mm long; 0.5–0.66 length of spikelet; chartaceous; without keels; 3–5 -veined. Upper glume margins tuberculate; ciliate. Upper glume apex emarginate.

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; without hair tufts, or with basal tufts of hair; 0–1 hair tufts in all; ciliate on margins (above); bearing white hairs; acute. Palea of lower sterile floret becoming indurate on flanks at maturity. Fertile lemma elliptic; 2.8 mm long; coriaceous; without keel. Lemma surface papillose and striate; with conspicuous apical hairs. Lemma margins involute. Lemma apex acute. Palea coriaceous.

FLOWER Lodicules 2; fleshy; truncate. Anthers 3.

DISTRIBUTION South America: northern South America, western South America, and Brazil.

NOTES Paniceae. Burman 1993.

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