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 longiligulata

HABIT Perennial; caespitose. Culms erect, or geniculately ascending; 30–60 cm long; without nodal roots, or rooting from lower nodes. Culm-nodes glabrous, or pubescent. Lateral branches ample. Leaf-sheaths mostly shorter than adjacent culm internode; keeled. Ligule an eciliate membrane; 1.5–2 mm long; erose. Leaf-blades 8.5–18 cm long; 2.5–5.5 mm wide. Leaf-blade surface pubescent; hairy adaxially. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence composed of racemes; terminal and axillary.

Racemes 1; single; arcuate; unilateral; 2.4–6 cm long. Rhachis narrowly winged; folded longitudinally to embrace spikelets; 2 mm wide; glabrous on surface; ciliate on margins; terminating in a barren extension; extension flattened. Rhachis hairs 0.5 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; pubescent.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; acute; 2–2.5 mm long; 0.8 mm wide; falling entire.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume oblate; 0.1 mm long; 0.05 length of spikelet; membranous; without keels; 0 -veined. Lower glume lateral veins absent. Lower glume apex truncate. Upper glume elliptic; 0.9 length of spikelet; chartaceous; without keels; 5 -veined. Upper glume surface asperulous. Upper glume apex dentate; 2 -fid.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret oblong; 1 length of spikelet; chartaceous; sulcate and readily splitting into two halves; glabrous; dentate; 2 -fid. Palea of lower sterile floret becoming indurate on flanks at maturity; 1 length of lemma. Fertile lemma elliptic; 1.5 mm long; coriaceous; without keel. Lemma surface papillose. Lemma margins involute. Lemma apex acute; without ornament. Palea coriaceous.

FRUIT Caryopsis ellipsoid. Embryo 0.4–0.5 length of caryopsis. Hilum linear.

DISTRIBUTION South America: Brazil.

NOTES Paniceae. Bastos & Burman 2004.

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