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.

Mesosetum comatum

HABIT Perennial; caespitose. Rhizomes elongated. Culms erect; slender; 30–60 cm long. Culm-nodes glabrous. Leaves differentiated into sheath and blade. Leaf-sheaths glabrous on surface; outer margin hairy. Ligule a fringe of hairs; 0.5 mm long. Collar pubescent. Leaf-blades 3–9 cm long; 2–6 mm wide. Leaf-blade surface glabrous to hirsute; hairy on both sides.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 1; single; unilateral; 4–8 cm long. Rhachis angular; ciliate on margins. Spikelet packing adaxial; regular; 2 -rowed.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong; 0.5 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; laterally compressed; 3.5–4.2 mm long; falling entire. Spikelet callus pubescent.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume oblong; asymmetrical; 2.8–3.2 mm long; 0.7–0.8 length of spikelet; chartaceous; 1-keeled; 3 -veined. Lower glume surface pilose; hairy below; with tubercle-based hairs. Lower glume hairs white; 3 mm long. Lower glume apex emarginate, or obtuse. Upper glume lanceolate; 2.8–3.2 mm long; 0.7–0.8 length of spikelet; membranous; without keels; 3 -veined. Upper glume margins ciliate. Upper glume hairs white. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; 1 length of spikelet; membranous; 5 -veined; with dorsal tufts of hair; 1 hair tufts in all; tuberculate on margins; ciliate on margins; bearing hairs 3 mm long; acute. Fertile lemma ovate; dorsally compressed; 3.2–3.6 mm long; coriaceous; without keel; 5 -veined. Lemma surface smooth. Lemma margins flat. Lemma apex acute. Palea coriaceous; without keels.

FLOWER Anthers 3; purple.

FRUIT Caryopsis ellipsoid; 2–2.4 mm long; dark brown. Embryo 0.66 length of caryopsis. Hilum linear; 1 length of caryopsis.

DISTRIBUTION South America: southern South America.

NOTES Paniceae. Filgueiras.

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