Black spine agave is a very distinctive small to medium-sized Agave with a leaf rosette that can be basal or can grow on a very short stem. Leaves are succulent, grayish green and up to 1.8 feet (55 cm) long, ending in sharp black spines that are up to 1.2 inches (3 cm) long at the tips. Flowers are small, grey, and red, growing in bunches on sturdy stems of up to 10 feet (3 m) in height.