Global description
Hackelochloa granularis is an upright and branched tufted grass, with distichous leaves, mostly hispid, with a broadly auriculate and embracing base. The ligule is short and membranous. The inflorescence comprises several groups of 2 to 4 racemes linear and long pedunculated, subtended by a leafy spathe. The sessile spikelets are fertile, they have a very hard and strongly wrinkled lower glume, including the spikelet. They are surmounted by a spikelet with a pedicel fused to the rachis and composed of oval foliaceous glumes. The grain remains included in the sessile spikelet.
First leaves
The first leaves have a folded prefoliation and are arranged in a distichous manner. The blade is oblong to lanceolate, 2 to 8 cm long and 8 to 10 mm wide. The base is broadly auriculate and almost embracing, the top is wide. The margin is wavy and strongly ciliated. The blade is erect obliquely, it is abundantly hispid or glabrous. The main rib forms a gutter. The ligule is short and membranous. The sheath is compressed and abundantly hispid with stiff hairs at the base or sometimes glabrous.
General habit
Hackelochloa granularis is erect, in isolated branched individuals or in upright tuft abundantly branched. This species is up to 1 m tall.
Underground system
The roots are fasciculate.
Culm
Culm is compressed, 2 to 4 mm wide. It is streaked longitudinally and hispid with tubercle hairs or glabrous. The knots are dark in color.
Leaf
The leaves are alternate and distically arranged, erect obliquely and distributed throughout the culm. The sheath is compressed and weakly keeled. It is hispid, with strongly ciliated margin or glabrous. The ligule is membranous and 0.3 mm high. The lamina is linear lanceolate, at the top in acute corner. It is 8 to 20 cm long and 8 to 12 mm wide. It is largely auriculate at the base, partially embracing the culm. It is hispid, stiff-haired, tubercular at the base, or glabrous. The margin is ciliated, more or less wavy. The main rib forms a little marked gutter.
Inflorescence
The inflorescence is branched, composed of several groups of 2 to 4 linear racemes subtended by a spathe resembling a leaf. The racemes are 5 to 15 mm long and long stalked. The rachis is articulated and very fragile.
Spikelet
Spikelets are of two very different types. Sessile spikelets are globose and verrucose, 1 mm long. The lower glume is globose, very hard and strongly wrinkled longitudinally and transversely, it almost completely encompasses the spikelet. The upper glume is oval and cartilaginous. It is contiguous to the rachis. Lemma and palea are membranous. Each sessile spikelet is surmounted by a pedicellate spikelet. Pedicellate spikelets are borne by a short pedicel welded to the rachis. The lower and upper glumes are oval elliptical and look like very small leaves. They are marked by 5 longitudinal ribs and are 1.5 mm long. Pedicellate spikelets are sterile and remain green. Sessile spikelets are fertile and are greenish yellow in color, becoming dark brown. At maturity, the raceme breaks down at the level of each internode of the rachis. The organ of dissemination is constituted by the sessile spikelet and its rachis portion.
Grain
Grain remains included in the lower glume of globose sessile spikelets. It is orbicular, with a diameter of 1 mm. The tegument is smooth, light orange in color.