The WOOD is rather soft, light, coarse-grained, and durable, in contact with the soil. It is used for fence posts, poles and fuel, and occasionally for railroad ties. It is a mistake to attempt to grow catalpa for fence posts or other uses except on good agricultural soil.
SOUTHERN CATALPA (C. bignonioides Walt.) has a thin, scaly [bark], abruptly short-acuminate leaf, [fetid] when crushed. Margin of lower lobe of flower entire. The valves of the [capsule] flatten after dehiscence. The [terminal] tuft on the seed forms a point.
DESERTWILLOW
Chilopsis linearis (Cav.) Sweet
This interesting tree, so named because of its willow-like leaves, is closely related to the catalpa. Often reaching a height of 25 feet and a diameter of 10 to 12 inches, it is found usually in dry, gravelly, [porous] soils in the valley of the lower Rio Grande and through West Texas.
The LEAVES are less than ½ inch wide and from 6 to 12 inches long, light green, and pointed. Their arrangement on the twig is either [opposite] or [alternate].
DESERTWILLOW (Leaf, one-third natural size; [fruit] and flowers, one-half natural size)
The white FLOWERS shade into pale purple and are blotched in their “throats” with pale purple. They occur in an [elongated] cluster, or raceme, opening successively toward the end of the flower stalk.
The [FRUIT] “[pods]” are [capsules] 7 to 12 inches long, hard or woody, very slender, and contain numerous small seeds.
The soft, weak, close-grained WOOD is brown streaked with yellow. The [sapwood] turns to [heartwood] in 2 or 3 years.