Identifying characteristics:
The catalpa is a medium to large (30 to 60 ft) deciduous tree with an open,
irregularly pyramidal or oval crown. It is easily identified by its large,
broad, tropical-looking leaves which are
4 to 11 inches long and 3 to 7 inches wide with a heart-shaped base and
a long, pointed tip. The leaves are simple and the leaf margins entire.
The leaves are papery or even leathery above, paler and softly hairy beneath
and are arranged in whorls of three. Petioles are stout, round and 5 to
6 inches long.
Catalpas begin producing fruit and flowers at about 15 years of age, flowering
in early spring after the leaves have appeared. Showy white, tubular flowers are borne in open clusters at the
ends of the branchlets and each flower has indistinct yellow and purple
spots on the inner surface. Winter buds: A terminal bud is absent, and the
side buds, which are partially imbedded in the bark of the twigs, are small
and globose, with about 6 loosely-attached scales. The large, round leaf
scars with a circle of bundle scars are quite distinctive on the twigs.
The 8 to 20-inch-long, round, dark-brown, cigar-shaped pods
(capsule) mature in the fall and split into two halves to release numerous
flattened, light brown, propeller-shaped, winged seeds. Catalpa bark is rather thin, brown or gray, developing small,
scaly plates and eventually furrowed with short, shallow, scaly ridges.
Similar species:
- Red mulberry (Morus rubra)
Ecology:
Native to the boot-heel region of south east Missouri, the northern catalpa
was recognized by settlers as being a useful, adaptable, fast-growing, hardy
species. It grows well throughout the Midwest, is cultivated throughout
Iowa and often persists in abandoned farmsteads and is occasionally found
along roadsides and stream banks. Tolerant of a variety of soil types, it
will, however, grow best in moist, rich soils. Verticillium wilt is the
most serious disease, killing many catalpas planted as ornamentals. In wet
years powdery mildew may attack the foliage, but the tree will continue
to prosper. Due to the weak wood, the branchlets break easily in strong
storms.
Uses:
Wood of the catalpa tree is light, soft and weak, but naturally durable
when properly seasoned. In the 1930's catalpa groves were planted across
Iowa and the Midwest as it gained a reputation of producing good quality
fence posts quicker than any other tree. Today it is not an important timber
tree but it is occasionally used for posts, rails, interior finish, cabinetwork
and firewood.
Once popular as an ornamental, it is now seldom planted. In the autumn the
color is poor and the leaves and pods can create a large amount of debris
when they fall. Although a very handsome tree, its large size should be
taken into consideration before planting in a small yard.
