This rounded, deciduous tree eventually has widespreading branches which are green when young and covered with spines, often becoming grey and sometimes losing their coarse, sharp spines, Young trees can have a columnar or upright form. The spiny trunk is unusually thick and remains green even on older trees. Floss-Silk tree grows rapidly the first few years, then more slowly. Some trees maintain a relatively narrow crown with one straight trunk while others are wide-spreading, particularly on older specimens. The large, showy, pink and white, five-petaled flowers, which somewhat resemble narrow-petaled hibiscus, are produced in small clusters in fall and winter (usually October) when the tree is nearly bare. The fruits are large, eight-inch-long, pear-shaped, woody capsules, filled with silky, white, kapok-like floss and pea-like seeds. Floss from the seeds was used for stuffing pillows and thin strips of the bark have been used to make rope.