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.

Munroa argentina

HABIT Annual; mat forming. Stolons present. Culms decumbent; 5–10 cm long. Culm-internodes alternately elongated and bunched. Lateral branches ample. Leaf-sheaths 0.5 cm long; outer margin hairy. Ligule a fringe of hairs. Leaf-blades flat, or conduplicate; 1–2 cm long; 1 mm wide; stiff. Leaf-blade surface scabrous; rough adaxially. Leaf-blade margins cartilaginous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence comprising only a few spikelets; comprising 2 fertile spikelets; terminal and axillary (in a leafy fascicle); shorter than basal leaves; deciduous as a whole; subtended by an inflated leaf-sheath (2 sheaths); embraced at base by subtending leaf. Peduncle disarticulating; disarticulating below uppermost sheaths.

Spikelets solitary. Fertile spikelets sessile; heteromorphic (upper with bifid upper glume).

FERTILE SPIKELETS Spikelets comprising 2 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 4–5 mm long; falling entire; deciduous with accessory branch structures. Floret callus pubescent.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume lanceolate; 1 length of upper glume; membranous; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex acuminate. Upper glume lanceolate; 4–5 mm long; 1 length of adjacent fertile lemma; membranous; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acuminate.

FLORETS Fertile lemma oblong; 4–5 mm long; chartaceous; without keel; 3 -veined. Lemma surface scaberulous; with marginal hair tufts; bearing 2 hair tufts in all. Lemma apex dentate; 3 -fid; awned; 1 -awned. Principal lemma awn apical; 1 mm long overall.

FLOWER Anthers 2; 1.5 mm long. Stigmas 2.

FRUIT Caryopsis with adherent pericarp; ovoid; laterally compressed; smooth. Embryo 0.5 length of caryopsis; projecting below grain. Endosperm flinty (translucent).

DISTRIBUTION South America: western South America and southern South America.

NOTES Eragrostideae. Parodi.

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