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.

Melica commersonii

HABIT Perennial; caespitose. Butt sheaths herbaceous; not bulbous, or thickened and forming a bulb; pilose. Culms erect, or rambling; 20–120 cm long. Leaves mostly basal. Leaf-sheaths tubular for much of their length; with 1 of their length closed; smooth, or retrorsely scabrous; glabrous on surface, or pilose; with reflexed hairs. Ligule an eciliate membrane; 2–7 mm long; lacerate. Leaf-blades 2.5–17 cm long; 1.5–3.5 mm wide. Leaf-blade surface scabrous (retrorsely); pilose; hairy adaxially, or on both sides; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear; secund; 5–18 cm long. Primary panicle branches appressed; simple. Panicle axis dominant; scabrous. Panicle branches scabrous.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; curved; ciliate; hairy all along but hairs longer above.

FERTILE SPIKELETS Spikelets comprising 2–3 fertile florets; with diminished florets at the apex. Spikelets elliptic; laterally compressed; 6–11 mm long; falling entire. Rhachilla internodes scaberulous. Floret callus pubescent.

GLUMES Glumes dissimilar; with lower wider than upper; exceeding apex of florets; thinner than fertile lemma. Lower glume obovate; 6–11 mm long; 1.5–2 length of upper glume; membranous; much thinner above; much thinner on margins; purple; without keels; 7–9 -veined. Lower glume surface asperulous. Lower glume apex erose; obtuse. Upper glume lanceolate; 5.5–7 mm long; 1.1 length of adjacent fertile lemma; membranous; much thinner above; with hyaline margins; mid-green, or purple; without keels; 5 -veined. Upper glume surface asperulous. Upper glume apex erose; obtuse.

FLORETS Fertile lemma oblong; 4.5–6 mm long; 2–2.5 mm wide; chartaceous; much thinner above; much thinner on margins; without keel; 9–11 -veined. Lemma surface scaberulous. Lemma margins eciliate, or ciliate; hairy in the middle. Lemma hairs 1–1.2 mm long. Lemma apex erose; emarginate, or obtuse. Palea 2 -veined. Palea keels ciliolate. Palea surface scabrous. Apical sterile florets barren; in a clump; cuneate; 1.5–2.5 mm long. Apical sterile lemmas truncate.

FLOWER Lodicules 2; united; oblong; 0.3–0.5 mm long; fleshy; glabrous, or ciliate; truncate. Anthers 3; 1.5–2.2 mm long.

FRUIT Caryopsis with adherent pericarp; 3 mm long; dark brown. Embryo 0.33 length of caryopsis. Hilum linear; 1 length of caryopsis.

DISTRIBUTION South America: southern South America.

NOTES Meliceae. Schick 1995.

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