Global description
Brachiaria lata is a plant with lanceolate to linear leaves. The sheath is ciliated especially on the margin. The ligule is ciliated. The base of the lamina is enlarged and both sides are covered with long hairs. The inflorescence is a panicle of linear racemes 2 to 5 cm long with ellipsoid spikelets 2.5 to 3.5 mm long, 2-flowered. The lower glume measures 1/3 to 1/2 of the length of the spikelet. The lemma and palea surrounding the grain are hard and rough.
First leaves
The first leaves have a rolled prefoliation. The blade is lanceolate and auriculate at the base. It is 2 to 5 cm long and 10 mm wide. The ligule is long ciliated. The outer side of the sheath is covered with long white hairs at the base. The margin is long ciliated and slightly cartilaginous. Both sides are long pubescent. The central rib forms a small hull.
General habit
The plant is tuft, first spread and then erect, which allows rooting at the nodes of the base. The branches ramify at the nodes of the base. The plant can reach 30 to 150 cm in height.
Underground system
The roots are fasciculate.
Culm
The culm is cylindrical, finely streaked longitudinally and glabrous. The nodes are dark, compressed and pubescent.
Leaf
The leaves are alternate, of light green to yellowish hue. The sheath is abundantly ciliated on the outer surface, sometimes glabrous, and not keeled. The margin of the sheath is always provided with long white lashes, mute at the base. The ligule is formed of eyelashes, arranged in a single row and 2 mm high. The limb is lanceolate to linear. It is 10 to 25 mm wide and 5 to 20 cm long. The base of the blade is rounded and auriculate, embracing the stem above the ligule. The summit is sharp peak. The margin is cartilaginous, abundantly ciliated at the base then strongly scabrous. Both sides are abundantly provided with hairs tuberculated at the base. The central vein forms a small rounded hull of white color.
Inflorescence
The inflorescence is a panicle composed of 5 to 15 racemes, sessile, obliquely erect and distributed along the axis glabrous to slightly pubescent, 5-15 cm long. The racemes are linear, 2 to 5 cm long. They bear single or closely spaced spikelets, one of which is sessile and the other briefly pedicellate, on the lower sides of a triangular section rachis, 0.5-1 mm wide. The spine is finely pubescent.
Spikelet
Spikelets are all alike. They have two flowers. The lower flower is male or asexual while the upper flower is bisexual. Both flowers are similar in size. The spikelets are ellipsoid in shape, dorsally compressed, with pointed apex. They measure 2.5 to 3.5 mm long and 1.5 mm wide. They are hairless and have at the base a few lashes 1 to 3 mm long. The lower glume is oriented towards the axis of the raceme. It is oval, at the top in wide corner and measures 1/3 to 1/2 of the length of the spikelet. It has 3 to 5 veins. The upper glume is oval and as long as the spikelet. It has 5 to 7 longitudinal ribs. The palea of the lower flower is as long and broad as the spikelet. The lemma of the lower flower is reduced to a narrower membranous part. The palea of the upper flower is elliptical and mucronate at the top. It is 2.5 mm long and has a rough, hard surface. The edges slightly cover the palea which has the same rough and hard appearance.
Grain
The grain is ellipsoidal and 2 mm long. During the spread, it remains locked in the palea and the lemma.