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.

Mesosetum cayennense

HABIT Perennial; caespitose. Culms erect; 35–140 cm long. Culm-nodes glabrous. Lateral branches lacking, or sparse. Leaf-sheaths outer margin glabrous, or hairy. Ligule a fringe of hairs; 1 mm long. Leaf-blades 4.5–20 cm long; 3–6 mm wide. Leaf-blade surface glabrous to hirsute.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; flexuous; unilateral; 5–15 cm long. Rhachis angular. Spikelet packing adaxial; irregular; 2 -rowed.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong; 0.7–1 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 3.8–4.2 mm long; falling entire. Spikelet callus pubescent.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; 2.8–3.1 mm long; 0.75 length of spikelet; chartaceous; 1-keeled; 3 -veined. Lower glume surface pilose; hairy below. Lower glume hairs red. Lower glume apex erose; truncate. Upper glume ovate; 3.5–4 mm long; 0.9 length of spikelet; membranous; without keels; 3–5 -veined. Upper glume surface pilose; hairy at base and on veins; with marginal tufts of hair. Upper glume margins ciliate. Upper glume hairs red. Upper glume apex entire, or dentate; 2 -fid; acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 1 length of spikelet; membranous; thicker on margins; 3 -veined; with marginal tufts of hair; 2 hair tufts in all; obtuse. Fertile lemma ovate; dorsally compressed; 3–3.2 mm long; coriaceous; without keel; 5 -veined. Lemma margins flat. Lemma apex acute. Palea coriaceous; without keels.

FLOWER Anthers 3; purple.

FRUIT Caryopsis 1.5–2 mm long; dark brown. Embryo 0.66 length of caryopsis. Hilum linear; 1 length of caryopsis.

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

NOTES Paniceae. Filgueiras.

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