Heteropogon contortus - Black Speargrass

Black Speargrass is tropical, perennial tussock grass, growing up to 1.5 m tall. The plants develop characteristic dark seeds with a single long awn at one end and a sharp spike at the other. The awn becomes twisted when dry and straightens when moistened, and in combination with the spike is capable of drilling the seed into the soil. The leaves are green or bluish green, usually glabrous or with few long hairs at the base. The leaf-blade is folded when young, then flat at maturity, 3-30 cm long, 2-8 mm broad, and somewhat canoe-shaped at the apex. The inflorescence is a 3 to 8 cm long raceme borne single or in pairs at the axil of the upper leaves. The spikelets are paired and very dissimilar according to their position on the raceme. Male or sterile spikelets are awnless, stalkless and borne at the base of the raceme, or pedicellate and borne at the apex. Bisexual spikelets are only borne at the apex and they are all awned. The long awns, 5-10 cm long, and the way they become twisted as the seeds mature are a characteristic trait of spear grass. The seed is a caryopsis, 3.5-4.5 mm long, grooved and whitish in color. Spear grass is mainly used as fodder when it is young. It can be grazed or cut for hay or silage.