Catalpa
Catalpa speciosa | Bignoniaceae
Submission: E.J. Holm & Liya Simon
Identification:
Leaves- Large (8-12”) and heart-shaped (cordate), with a tapering, pointed (acuminate) tip. Yellowish-green color, with a slightly lighter underside that is pubescent (covered with a layer of hairs). Yellow in the fall.
Twigs- Round leaf scars are sunken into the twig, making the tree easily recognizable even in winter. Leaves (and therefore their scars) are whorled in groups of three to a node on younger branches, and opposite on older branches.
Flowers- The much-beloved flowers are bell-shaped, white with yellow, orange, or purple streaks inside, and arranged in clusters up to 10” long.
Fruit- Seed pods produced in the summer are green, bean-shaped and enormous, from 10 to 24” long. In the fall, they turn dark brown and split open down the middle.
Bark- Light grayish-brown with a range of textures in adults; thin and easily damaged on young trees.
Natural History:
“Catalpa” is the name of a genus of flowering, deciduous trees that are commonly planted as ornamentals due to their large, shade-providing canopy and beautiful, white flowers. While they grow rapidly when young, their growth rate plateaus as they mature, and their lifespan is usually about 60 years. Catalpas grow best in areas with a lot of light, with moist, well-drained soil, but are adaptable to a wide range of conditions.
Two primary species of Catalpa grow in Maine: the Southern Catalpa (Catalpa bigonioides) and the Northern Catalpa (Catalpa speciosa). Only the latter can be found on the Bates campus. The original range of the Northern Catalpa is believed to have been a small section of the Midwest near the meeting of the Mississippi and Ohio rivers, but its range has expanded to include most of the United States. Southern Catalpas are native to the southwestern coast of America (Florida, Georgia, Alabama, etc) but, like their northern counterparts, have naturalized widely throughout the country, including Maine.
The word “Catalpa” comes from the Cherokee and Muskogee word for the tree, and is a combination of the words for “head” and “wing”. Its species name, speciosa, comes from a Latin word meaning “showy,” because of the tree’s large white flowers. Catalpa goes by many nicknames, and is sometimes referred to as the Catawba tree, worm tree, or Indian bean. One of the key identifying characteristics of the Catalpa are its long seed pods, which are green in the summer and grow from 10 to 24 inches long. They mature in the fall and turn dark brown, looking somewhat like cigars, which granted the Catalpa its other common nickname of “cigar tree.” These pods split open naturally in the fall to release seeds, which are about one inch long, light brown, and winged.
The Catalpa tree has a long history of use in indigenous herbal medicine. The bark, seeds, and seed pods of the tree can be turned into a decoction or tea, and were historically used for a wide variety of purposes, including as an eyewash and as a treatment for malaria, asthma, bronchitis, whooping cough, and cardiac problems. The pods and seeds are also known to possess a mild narcotic or sedative effect, so the Catalpa was commonly used for flushing wounds and treating swollen lymph nodes. However, not all parts of the plant are beneficial— the roots of the Catalpa are highly poisonous, which has granted the Catalpa an unfortunate (and unfounded) reputation as a wholly toxic plant.
Catalpa trees have their fair share of commercial uses. Its wood is soft, yet rot-resistant and durable, making it valuable for usage in carved cabinetry, woodturning, interior decoration, fencing, and railroad ties. Catalpa trees are beloved by those who like to fish because the caterpillars of the Catalpa sphinx moth (Ceratomia catalpae) make excellent fishing bait. These worms feed exclusively on the leaves of the Catalpa tree, so many fishers will plant Catalpas specifically for the purpose of attracting them to their yard.
References:
United States Department of Agriculture and National Resources Conservation Service. (2005,
June). Northern Catalpa. USDA-NRCS Plants Database.
United States Department of Agriculture. (2014). Catalpa bignonioides Walter. USDA Plants
Database. https://plants.usda.gov/home/plantProfile?symbol=CABI8
Merriam-Webster. Catalpa. https://www.merriam-webster.com/dictionary/catalpa#word-history
United States Department of Agriculture. (2014). Catalpa speciosa (Warder) Warder ex
Engelm. USDA Plants Database.
5) “Catalpa speciosa.” (2023, November 4). In Wikipedia.
6) United States Department of Agriculture and National Resources Conservation Service.
(2021, August 11). Southern Catalpa. USDA-NRCS Plants Database.
8) Baker, James. (2021, May 24). Catalpa Worm or Catalpa Sphinx. NC State Extension
Publications. https://content.ces.ncsu.edu/catalpa-worm-or-catalpa-sphinx
9) Chevallier, A. (2023). Encyclopedia of Herbal Medicine. DK Publishing.