A slow growing, evergreen tree to about 9m (30′) tall. Its palm-like trunk has a massive, swollen base, which may reach 3 metres (10′) in diameter. The trunk tapers upward and then branches, with each branch supporting a dense crown of long, strappy leaves. Ponytails are dioecious, that is male and female reproductive parts are on separate plants. Masses of small white flowers are produced in summer, followed by spectacular stems of pinkish, 3-winged seeds on mature female plants.