Catalpa, also called catawba, is a genus of flowering trees native to warm, temperate climates of North America, the Caribbean, and east Asia. Most catalpas are deciduous, meaning they lose their leaves seasonally. The trees grow to be 39 to 59 feet (12 to 18 meters) in height.
Catalpas have large, heart shaped leaves with three lobes, white to yellow flowers, and long fruits that resemble bean pods. Their wood is soft and is sometimes used as tonewood in guitars. The large leaves produce dark shade, providing shelter for many species of bird.
Some species of Catalpa are grown outside their natural range as ornamental plants, including the Chinese C. ovata, or Yellow Catalpa, and the North American plants C. bignonioides, or Southern Catalpa, and C. speciosa, or Northern Catalpa. C. ovata features creamy, pale yellow flowers that bloom in July and August. C. bignonioides and C. speciosa are also referred to by the common names Indian bean tree and cigar tree, due to the distinctive shape of their fruit.
C. bignonioides is native to the southeast United States, with a range extending through Alabama, Florida, Georgia, Louisiana, and Mississippi. C. speciosa, also called Western Catalpa and Hardy Catalpa, is native to the midwestern States of Arkansas, Illinois, Indiana, Kentucky, Missouri, Pennsylvania, and Tennessee. Though the two species are very similar in appearance, C. speciosa can be distinguished by its larger flowers and seed pods. The flowers of C. bignonioides are smaller, but grow in greater quantities.
Both C. bignonioides and C. speciosa have brittle wood, but the wood of C. bignonioides is harder. The wood of both trees has been traditionally used to make railroad ties and fence posts because of its resistance to rot, but more recently, C. speciosa wood has also been used in cabinetry, interior trim, furniture, carving, and boat building. The wood also has the lowest rate of shrinkage and expansion of any native hardwood in the United States.
C. bignonioides is the only food source of the Catalpa Sphinx moth (Ceratomia catalpae). The caterpillars, or "catawba-worms," are a prized fishing bait and are harvested from the trees. Some fishermen plant small orchards of C. bignonioides in order to have their own supply of bait.
C. brevipes has one of the smallest geographical ranges within the genus, growing only in parts of Cuba, the Dominican Republic, and Haiti. The tree's natural habitat is forests with dry limestone soil. C. brevipes is of vulnerable conservation status.