Sansevieria

From Wikipedia:
S. cylindrica has striped, round leaves that are smooth and a green-gray color. A single leaf is about 3 cm (1 in) thick and grows to a height between 1 m (3 ft) and 2 m (7 ft).[1] The Spear Sansevieria grows fan-shaped, with its stiff leaves growing from a basal rosette. The species is interesting in having rounded instead of strap-shaped leaves caused by a failure to express genes which would cause the cylindrical bud to differentiate dorsoventrally or produce a distinctive and familiar top and bottom surface to the leaf blade. The plant blooms once a year in the spring or mid-summer, producing 3 cm (1 in) greenish-white tubular flowers tinged with pink. The species is drought-tolerant and in captivity needs water only about once every other week during the breeding season.