Melica rigida

Melica rigida is a species of grass found in Argentina, Brazil (Santa Catarina, Rio Grande do Sul), and Uruguay.

Description
The species is perennial with short rhizomes. It culms are erected and 20 - 75 cm long while the plant stem is smooth. The leaf-sheaths are scabrous, tubular, closed on one end and are glabrous on surface. The leaf-blades are flat, stiff, and are 3 – long by 2 – wide. They also have scabrous margins and surface, the later one of which is rough. The eciliate membrane have a ligule which is 0.5 – long and have a pubescent surface. The panicle is open, linear, and is 6 – long by 1 – wide. The main panicle branches are appressed with scaberulous and dominant axis.

It spikelets are elliptic, solitary and are 8 – long. Fertile spikelets have pedicels which are curved filiform, and scabrous. They also have 2 fertile florets which are diminished at the apex with its rhachilla internodes being scaberulous. The floret callus is pubescent and have hairs which are 0.1 – long. The glumes are dissimilar and are keelless and membranous, with other features being different; Lower glume is obovate, 8 - 11 mm long with an obtuses apex, while the upper one is lanceolate, 4 – long and have an acute apex.

Lemma have ciliated margins, scaberulous surface, acute apex with the hairs being 0.5 mm long. It fertile lemma is chartaceous, elliptic and is 5.5 – long by 2 – wide. The species' palea have ciliolated keels, smooth surface and dentated apex. Flowers are fleshy, oblong and truncate. They also grow together, 0.3 – long, have 2 lodicules and 3 anthers, the later one of which are 1 - 1.5 mm long. Fruits are dark brown in colour, have caryopsis and additional pericarp. They also have linear hilum while their size is 2.5 – long.

Ecology
In Brazil, the species is found growing in fields on the elevation of 1000 - 1200 m.