Melica commersonii is a species of grass endemic to Chile (Limari to Arauco).[1] [2]
The species is perennial and is caespitose as well. It culms are 20– long with butt sheaths being herbaceous and pilose. The leaf-sheaths are smooth, tubular and have one closed end. They are also have a glabrous surface that have reflexed hairs. The leaf-blades are 2.5– long and 1.5– wide and have a scabrous surface while the membrane is eciliated, lacerate, and is 2– long. The panicle is open, linear, secund and is 5– long. The main panicle branches are appressed and scabrous with panicle axis being dominant and scabrous as well.[2]
Spikelets are elliptic, solitary and are 6– long. They have fertile spikelets that are pediceled, the pedicels of which are ciliate, curved, filiform, and hairy. Lemma is chartaceous, lanceolated, and is 4.5– long and 2– wide. Its lemma have either erose or obtuse apex while the fertile lemma itself is chartaceous, keelless, oblong and is long. The species also carry 2–3 sterile florets which are barren, cuneate, clumped and are 1.5– long. Both the upper and lower glumes are oblong, keelless, membranous, and are purple in colour. Their size is different though; lower one is 6– long while the upper one is 5.5– long. Its palea have ciliolated keels and is 2-veined.[2]
Flowers are fleshy, oblong, truncate, have 2 lodicules and grow together. They are also glabrous, 0.3– long and have 3 anthers with fruits that are caryopsis. The fruit is dark brown in colour and have additional pericarp with a linear hilum.[2]
Melica commersonii grows along the coast, in the hills of the Coastal and Andran Cordillera on the elevation of and above sea level.[1]