Catalpa bignonioides Southern Catalpa. It is a medium-sized deciduous tree growing to 15–18 metres (49–59 ft) tall, with a trunk up to 1 metre (3 ft 3 in) diameter, with brown to gray bark, maturing into hard plates or ridges. The short thick trunk supports long and straggling branches which form a broad and irregular head. The roots are fibrous and branches are brittle, its juices are watery and bitter tasting.
The leaves are large, bright green and heart shaped, being 20–30 cm (7.9–11.8 in) long and 15–20 cm (5.9–7.9 in) broad. They appear late, and as they are full-grown before the flower clusters open, they add much to the beauty of the blossoming tree. They secrete nectar, a most unusual characteristic for leaves, by means of groups of tiny glands in the axils of the primary veins.