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 seminuda

HABIT Perennial; caespitose. Butt sheaths pubescent. Culms erect, or geniculately ascending; 100 cm long. Culm-internodes distally pubescent. Culm-nodes bearded. Leaf-sheaths keeled; hirsute. Leaf-sheath oral hairs bearded. Ligule an eciliate membrane; 5–6 mm long; acute. Leaf-blades 12–30 cm long; 4–7 mm wide. Leaf-blade surface puberulous; hairy adaxially. Leaf-blade margins glabrous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; arcuate; unilateral; 14–30 cm long. Rhachis broadly winged; folded longitudinally to embrace spikelets; 3–4 mm wide; glabrous on surface; pubescent on margins; terminating in a barren extension; extension flattened. Rhachis hairs white; 3–4 mm long. 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; dorsally compressed; 3.5–4 mm long; 1.2 mm wide; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 0.5 mm long; 0.1–0.2 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 1 length of adjacent fertile lemma; 0.9 length of spikelet; chartaceous; without keels; 5 -veined. Upper glume surface pilose; hairy at base. Upper glume margins ciliate. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret elliptic, or oblong; 0.9 length of spikelet; coriaceous; sulcate and readily splitting into two halves; with basal tufts of hair; 1 hair tufts in all; eciliate on midvein, or pubescent on midvein; ciliate on margins (above); 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. Lemma margins involute; ciliate; hairy above. Lemma apex acute; pubescent. Palea coriaceous.

FLOWER Lodicules 2; fleshy; truncate. Anthers 3.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Burman 1993.

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