Northern Catalpa

(Catapla speciosa [Warder ex Barney] Warder ex Engelm.)

Description

Northern catalpa (family Bignoniaceae¹), a perennial and deciduous tree², can reach heights of 98 feet and expand to approximately 30 inches or more in circumference with an appearance of peeling, gray bark and cordate (heart-like) leaves of deep green³. It lives approximately 60 years². The leaves pose in opposite or whorled patterns that can be 7-12 inches in length and 5-8.25 inches in width and are accompanied by white flowers of yellow stripes and purple polka dots amidst the center³. Northern catalpa flowers can reach widths of 2.25 inches and grow in clusters that can reach 7.75 inches³. The fruit of the flower can be long (14 inches) and narrow and can contain more than 100 winged seeds³.Northern catalpa grows at rapid rates in its juvenile stages but slows its growth rate after and after about 20 years.

Flowers of northern catalpa. @ J. Hull, 2020. TU

Northern catalpa leaves, flowers and fruit. @ J. Hull, 2020, TU

Distribution

Deep, moist, and non-flooded soils with a pH of 5.5 – 7.0 are preferred for ideal growth but the northern catalpa can adjust and adapt to soils of either extreme: wet soils and dry soils².Northern catalpas tend to congregate upon bottomlands such as the grounds near streams, rivers, or lakes and are generally positioned in wide, open spaces³. The native and non-native distribution differs. Its native distribution is from southern Illinois and Indiana to south to western Tennessee and Arkansas¹¹. Widely planted its current distribution is from New England, to North Dakota; south to Texas, Colorado, Utah and New Mexico; and east to Georgia and north to Pennsylvania. It is not recorded from New Jersey and Delaware.³ It is considered invasive in Maryland¹².

Current distribution of northern catalpa. EDD MapS ⁵

Wildlife importance

Northern catalpa is visited by flies, wasps, bees³ and humming birds⁴ for its flowers. One permanent residential species of the northern catalpa trees is the Catalpa Sphinx Moth⁴.

Economic importance

Due to its beauty and size, northern catalpa are planted for the purposes of aesthetics and shade and are generally planted along the sides of streets and in residential lawns². This helps reduce the absorption and reflection of heat by and from the earth and reduce temperatures. The wood has been used for making railroad ties, fence posts beams, furniture and millwork ^10,11.Other uses of the northern catalpa are for conservation purposes when land needs restoration after a mining project⁶.After destructive mining projects are complete, the sites are inhospitable with poor soils, high light conditions, hot conditions⁷, however, the northern catalpa can flourish and grow despite the environmental odds.

Threats

Northern catalpa are threatened by Ceratomia catalpa (a sphinx caterpillar) which consume the leaves leading to excess oozing of nectar and vulnerability to predacious insects. Rabbits consume the stem causing girdling. Yellow grub consumes the immature seeds. Cecidomyia catalpae, an invasive insect⁸ leaves behind leaf spots and damaged terminal buds, branch tips, and seed pods. Macrosporium catalpae, a fungus, creates brown spots; Polystictus versicolor, a decaying fungus. harms the tree after about 20 years of life (more common in the west). Verticillium causes the death of its branches and eventually kill the tree². Not only can northern catalpa be threatened, but they can also be threatening. Due to their rapid growth rate and pattern, northern catalpa are weedy and, in some cases, invasive, leading to displacement of other desired plant species⁶.

Interesting facts

The largest recorded northern catalpa resides in Indiana, USA with a height of 85 feet, expansion of 81 feet, a circumference of 290 inches².
Currently, research shows that catalpa trees contain diuretic properties, ² affecting ability and process of eliminating salt and water from the body⁹.
Catalpa seeds can aid in situations of cardiac arrest, spasms, and asthma¹⁰.
The Catalpa Sphinx Moth larvae are great for fish bait, and thus some northern catalpa are intentionally grown by fishers or fishing purposes¹⁰.
A slang name of the northern catalpa is the Cigarette Tree due to the elongation of the fruit of the tree¹⁰.
People who encounter the white flowers can sometimes experience skin irritation due to the chemicals produced by the tree that reside in the flowering cluster⁷.

References

Contributed by E. Jackson and D. Meador

Towson University Glen Arboretum