Global description
Eragrostis aspera is a tufted plant, with long and tapered leaves, marked with a line of long white periligular hairs. The ligule is ciliated and is doubled with a crown of long white hairs. The inflorescence is a loose panicle, ellipsoidal, composed of extensively pedicellate spikelets. They are laterally compressed, consisting of 10 to 25 flowers. The spikelets are dislocated from the end. The glumes, lemmas and paleas are membranous, with dorsal scabrous venation. The grain is orbicular, red in color.
First leaves
The first leaves have a rolled prefoliation. The leaf blade is very linear and tapered to the apex, 2 to 10 cm long and 2 to 4 mm wide. It is obliquely erect. The ligule is ciliated, coupled with a second row of long white hairs. The periligular line consists of a row of long white hairs forming whiskers on each side of the ligule. The sheath is cylindrical and bears few long white tuberculate hairs along the margin. The keel is round and slightly marked. The lamina is covered with several long white hairs. The margin and main veins are scabrous. The midrib forms a gutter.
General habit
Plant grows as a dense tuft. The plant has a high tillering, but the axis are slightly branched. This species measures 40 to 100 cm in high.
Underground system
The roots are fibrous. Sometimes some stilt roots at the base of the plant are observed.
Culm
The culm of the grass is cylindrical, 2 to 4 mm large. It is smooth and glabrous. The nodes are glabrous and dark in color.
Leaf
The leaves are alternate and erect obliquely. The sheath is cylindrical and slightly keeled. It has some long white tuberculate hairs near the margin, especially near the ligule. Ligule is ciliated and 0.5 mm high. It is lined with a crown of white hairs 5mm long. The Periligular line has a line of white hairs, 5 to 7 mm long and also whiskers on each side of the ligule. The lamina is linear, extensively tapering to the apex in a sharp point. It is 10 to 30 cm long and 4 to 10 mm wide. It is covered with several long white hairs at the base of the upper face. Margins and main veins are scabrous. The leaf blade is marked in the middle by a grooved central rib.
Inflorescence
The inflorescence is a loose ovoid to ellipsoidal panicle. It can reach 50 cm long. It is formed of a multitude of thin and flexuous branches, with a spikelet at the end. The axils of branches is marked by a small tuft of hairs.
Spikelet
The spikelets are extensively pedicellate. They are 10 to 25 mm long and 1 to 1.5 mm wide and often tinted purple. They consist of 10 to 25 identical flowers, laterally compressed. The terminal flowers are sometimes sterile. At maturity, the spikelets are disarticulated from the terminal flowers. The racheole is fragile and breaks when disarticulation. The glumes are oval, 1 to 1.5 mm long. The lemmas are elliptical and long of 1 to 1.7 mm. The paleas are slightly shorter and narrower. All parts are membranous and scabrous along the dorsal ridge.
Grain
The grain is free, orbicular, having a diameter of 0.5 mm. The seed coat is smooth and dark red in color.