catalpa

Leaf: Whorled with 3 at a node, simple; blades ovate, long-pointed at the tip, straight to heart-shaped at the base, 15 to 30 cm long, 10 to 20 cm wide; smooth along the edges; dark or dull green and smooth or sparsely hairy on the upper surface, paler and softly hairy on the lower surface; turning blackish in autumn; leafstalks 9 to 15 cm long.

Flower: Large, showy, several in upright, elongated cluster, appearing in May and June, the clusters up to 15 cm long, each flower up to 5 cm long; the petals white and lined with purple; arranged in a bell-shaped corolla of 5 unequal rounded fringed lobes.

Fruit: Long, beanlike fruit, 8 to 18 inches (20 to 46 cm) long, 1/2 to 5/8 inches (12 to 15 mm) in diameter; narrow, cylindrical, dark brown capsule, cigar-like, thick-walled, splitting into two parts; many flat, light brown seeds with two papery wings; maturing in autumn, remaining attached in winter.

Twig: Green, turning brown; stout; becoming hairless; with conspicuous lenticels; leaf scars in whorls of 3, with one of the 3 scars smaller than the other 2, round-elliptic, elevated, with 12 or more bundle traces.

Bark: Light brown to brownish gray or black; smooth when young, becoming rather deeply furrowed into scaly plates.

Form: Medium tree up to 60 feet tall; trunk diameter up to 3 feet; crown broad, widely spreading.

Discussion

The catalpa tree has light, soft and weak wood that is naturally durable and resistant to decay when properly seasoned. In the 1930's catalpa groves were planted across Iowa and the Midwest as this tree gained a reputation of producing good quality fence posts quickly, along with black locust and osage orange. Its use continued until metal fenceposts were developed and largely replaced wooden fenceposts.

Once popular as an ornamental, it is now seldom planted. Three liabilities exist in urban areas where it is found as both a shade and an ornamental tree. Northern catalpa drops fragments of its long fruits and fringed seeds from winter through spring, creating a cleanup chore. In addition, it often gets far too big for its allocated space in the landscape, and crowds out or casts too much shade on other desirable plants. Finally, its brittle wood, coupled with tree height, makes its branches at times subject to wind or ice damage. The fall color is poor.

The two catalpas in Illinois are hard to tell apart. This one usually has deeply furrowed bark, shorter clusters of flowers, petals merely lined with purple rather than spotted and leaves which are not unpleasantly scented when crushed.

Catalpa is native to Illinois and surrounding states such as southwest Indiana and northeast Arkansas. It is widely naturalized in the southeast United States.

October, 2002 DF	October, 2002 JZ	October, 2002 DF
October, 2002 JZ	March, 2003	March, 2003

N 39.27997^º W -89.88008^º
Between St. Paul's United Church of Christ and Heinz Funeral Home, 200 Block East Main, Carlinville, Macoupin County, IL.

Herbert S. Zim and Alexander C. Martin, Trees, 1956, Western Publishing Company, Inc.

Robert H. Mohlenbrock, Forest Trees of Illinois, 1996, Illinois Department of Natural Resources.