The genus Catalpa contains ten or eleven (North American Trees, 5th Edition) different species of trees. The Chinese variety, Catalpa ovata, which is on the City Park tree tour, is a native of China but has been introduced in the eastern part of North America.
Two species are native to this continent, Catalpa Speciosa and the southern version, Catalpa bignonioides Walt. Even though neither of the other species is tagged in the park, I am going to discuss them because catalpas are one of my favorites. The trees look very similar with their large leaves and long bean-like seed pods. Each also has clusters of flowers, with the native trees blooming earlier with larger blossoms than the Chinese variety.
The Northern Catalpa (C. speciosa) is native to all but eight western states and Florida and has been introduced into Ontario. The Northern Catalpa is the largest of the three trees, normally growing to 60′. The National Champion tree in Indiana is 78′ and with a 81′ crown spread. C. bignonioides, the southern catalpa, has a range which overlaps that of the northern. It can be found in most of the states where the larger tree doesn’t grow as well as in North Dakota. Although the Southern catalpa is normally only 30-40′ in height (The Tree Book, Dirr and Warren, 2019) the champion tree listed in 2017 is not much smaller than its northern counterpart (75′ x 82′).
The moniker fish-bait tree technically applies to the southern variety of this tree, but the catalpa doesn’t want for other names. They include the cigar-tree, Catawba, Indian-bean tree, caterpillar tree, and Western Catalpa, with the Northern and Southern species sometimes sharing the same alternate name.
The wood of the northern tree has been used as railroad ties, trim carpentry, telephone poles, fences, and furniture. The southern catalpa wood has been used for similar purposes, but its most interesting use is in plantations where it is grown to attract the the catalpa sphinx moth, which is used for fish bait! (The Tree Book, Dirr and Warren, 2019).
Bark from C. Bignonioides has been used to treat malaria. Other parts of the plant have been used for medical reasons, including the roots, although the current writeup from the USDA includes a warning in red that the roots of this plant are poisonous! Plants for the Future rates only the Chinese Catalpa as having possible edibility. The USDA does warn that the native trees may be invasive and weedy. Many people complain that the seed pods are messy and many don’t like the large leaves. My feeling is that the larger leaves make them easier to pick up! Even the New York Times took up the case of the catalpa with the story of its spread in the 19th century.
The Chinese Catalpa is smaller than the native trees. An additional use of its wood is in the making of a traditional Chinese instrument, the Qin.
The Chinese catalpa C 175 in the City Park Arboretum is along Sheldon Drive, just south of the Indian Magic Crabapple on the eastern side of the road, catty corner from the latrine on the west side of the road. The catalpa trees in town seem to leaf out and flower late in the season, so much so that if you own one, you start to worry it has died, yet the Chinese catalpa is even later. It looks quite scraggly even this late in June this year.