Native to South America. Heavy trunk is studded with thick spines; it is green in youth, turns gray with age. Leaves divided into 5-in.-long leaflets like fingers of a hand; they drop during autumn flowering or whenever temperatures fall below 27F. Large, showy flowers somewhat resemble narrow-petaled hibiscus blooms. Fast drainage and controlled watering are keys to success. Water established trees about once a month during the growing season; ease off in late summer to encourage more flowers. Need little pruning except to remove wayward or dead growth.
C. insignis. WHITE FLOSS SILK TREE. To 50 ft. tall and wide. White to pale yellow, 5- to 6-in. flowers. Blooms from fall into winter; stopped by frost.
C. speciosa. Grows 35 ft. a year for first few years, then more slowly to an eventual 3050 ft. tall and wide. Blooms in fall, bearing pink, purplish rose, or burgundy flowers to 4 in. or more across. Grafted selections include 'Los Angeles Beautiful', with wine-red flowers, and 'Majestic Beauty', a thornless selection bearing rich pink blooms.