Aloe cooperi is a usually stemless, tall-growing grass aloe, solitary to heights up to 1,2 m or in small groups grown from off-shoots. The plant is variable across its geographical distribution.
The 16 to 20 leaves are two-ranked or distichous, sometimes spiralling in old plants, even becoming rosette-like. The long, erect, succulent leaves are soft-textured, variably keeled, usually in their lower parts, somewhat V-shaped in cross-section. The outer surfaces of the leaves are heavily, irregularly white-spotted low down, the inner ones lightly spotted to unspotted, but slightly longitudinally lined. The other grass aloe species do not have keeled leaves and are mostly smaller.
The blade surfaces are smooth, sometimes tubercled. The cartilaginous margins are narrow and white, armed with firm but not hard, white teeth up to 2 mm long on lower leaf parts, while reducing in size to almost disappearing near the tip. The leaves become about 70 cm long and 6 cm wide at the base.
The species distribution is in the northeast of South Africa, from KwaZulu-Natal and Mpumalanga to Limpopo; also in Swaziland. Plants occur as far south as Margate and Port Shepstone and north to the Wolkberg Mountains.
The habitat is moist grassland and dry, rocky places from sea level to 1900 m. The species is not considered to be threatened in its habitat early in the twenty first century.
The variety, A. cooperi var. pulchra of the KwaZulu-Natal north coast, a smaller plant with deeply keeled leaves, toothed only in their lower parts and red flowers appearing late, is no longer upheld.
These plants are sometimes eaten, cooked as a vegetable; also used medicinally (Reynolds, 1974; Craib, 2005; Van Wyk and Smith, 2003; http://redlist.sanbi.org).