GrassBase - The Online World Grass Flora

Descriptions

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

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

Thrasya hitchcockii

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 50–100 cm long. Culm-internodes distally glabrous, or pilose. Culm-nodes pubescent. Leaf-sheaths keeled; glabrous on surface, or hirsute; with tubercle-based hairs; outer margin hairy. Ligule an eciliate membrane; 1 mm long; truncate. Leaf-blades linear, or lanceolate; 12–30 cm long; 4–6 mm wide. Leaf-blade surface pubescent and pilose; hairy on both sides. Leaf-blade margins ciliate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; arcuate; unilateral; 9–13 cm long. Rhachis broadly winged; folded longitudinally to embrace spikelets; 2 mm wide; glabrous on surface; glabrous on margins, or ciliate on margins (sparsely); 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; dorsally compressed; 3.5 mm long; 1.8 mm wide; falling entire.

GLUMES Glumes one the lower absent or obscure, or two; dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume oblate; 0.3(–2) mm long; 0.1–0.3 length of spikelet; hyaline; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume elliptic; 3.5 mm long; 1 length of spikelet; chartaceous; without keels; 5 -veined. Upper glume surface glabrous, or pilose; hairy at apex. Upper glume margins ciliate. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret elliptic; 1 length of spikelet; coriaceous; readily splitting into two halves; glabrous, or pubescent; hairy at apex; eciliate on margins; acute. Palea of lower sterile floret becoming indurate on flanks at maturity. Fertile lemma elliptic; 3 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 and northern South America.

NOTES Paniceae. Burman 1993.

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