Catalpa speciosa

Tree usually 10 - 15 m tall (can reach 30 m), trunk 40 cm - 0.75 m in diameter Leaves: opposite or whorled, dark green, 20 - 30 cm long, 15 - 20 cm wide, heart-shaped with long pointed tips, non-toothed or slightly lobed, hairy beneath. Flowers: borne in a loosely branched inflorescence (12 - 20 cm long), white with tiny yellow and purple spots, 6 - 7 cm long, fused tubular to bell-shaped petals, two-lipped with three lower and two upper lobes. Fruit: a long cylindrical capsule changing from green to brown, 25 - 50 cm long, 1.5 cm wide, persisting through winter and splitting into two in spring.The seeds are 2 - 3 cm long, two-winged, and fringed at the ends of the wings. Bark: reddish to grayish brown, deeply furrowed with scaly ridges. Twigs: stout, greenish purple, changing to orangish or reddish brown and darkening with age. Terminal buds: absent. Leaf scars: large and almost circular. Lateral buds: brown, tiny, and rounded.

Similar species: Catalpa speciosa and Catalpa bignonioides are very similar species. Catalpa bignonioides has smaller leaves, blooms about two weeks later, has more but smaller flowers, scaly bark, narrower pods, and an unpleasant odor when leaves are crushed.

Flowering: May to June

Habitat and ecology: This species, introduced from the southern U.S., sometimes escapes cultivation into disturbed weedy areas, floodplains, low woods, and along railroads.

Occurence in the Chicago region: non-native

Notes: The rot-resistant wood of this species is used for fence posts, railroad ties, cabinets, lumber, picture frames, and interior trim. Small branches tend to break in storms as the wood is brittle.

Etymology: Catalpa is the Native American name for this tree. Speciosa comes from the Latin word for showy.

Author: The Morton Arboretum

Tree to 30 m, with well developed trunk; lvs broadly cordate- ovate or rotund, to 3 dm, distinctly acuminate, hairy beneath; infls to 2 dm; cor white, marked with 2 yellow stripes and faintly purple-spotted, the limb 5-6 cm wide; fr 2-5 dm נ1-1.5 cm, with a stout quadrangular placenta; seeds 2.5 cm, the wings rounded at the end and with a flat fringe of hairs; 2n=40. Alluvial forests; s. Ind. to Ark. and Tex., often cult. farther n. and e., and sometimes escaped. May, June.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.

Flora of Indiana (1940) by Charles C. Deam

Indiana Coefficient of Conservatism: C = 0

Wetland Indicator Status: FACU

Diagnostic Traits: Bark of old trees fissured and ridged; bruised leaves without a fetid odor; lower lobe of corolla notched at the apex. 

Deam (1932): A pioneer was interviewed who settled in the Knox County Bottoms about three miles west of Decker, when the whole area was a virgin forest. He said the catalpa was an occasional tree in the bottoms throughout the area; that he did not recall that it was ever found in as low situations as the cypress; that the tree was as tall as its associates, straight, and usually about 6 dm. in diameter, and that he never saw a tree a meter in diameter; that on account of the durable quality of the wood it was cut for fence posts and rails.

The tree has been planted long enough in our area to definitely indicate that it should not be planted in any part of Indiana for economic purposes. The range of the catalpa sphinx which defoliatess the tree is rapidly increasing, and now ranges to the northern part of the state. In the southern part of the state the trees are usually defoliated twice each year by the larvae of this insect and as a consequence the trees make little growth.... A new insect is appearing which kills the young shoots, thus interfering with the upright habit of the tree.

The catalpa prefers a moist, deep, rich soil, but will grow in almost all kinds of situations. In the northern part of the state, the young trees are frequently winter killed. The tree is quite tenacious of life and when cut off at the ground, usually sends up several coppice shoots. 

This species can be recommended for planting for shade for hog lots and as a specimen tree in parks. It is not a desirable street tree.