You say, "Catalpa" and I say, "Catawba!" Both are correct common names for several species of the genus Catalpa. The tree was named for the Catawba Indians, and misspelled as Catalpa. In the U.S. there are two natives: Northern and a Southern, with the leaves, flowers and beans of the Northern being slightly larger. We were impressed by these we saw in Columbia, Missouri.
As the beans dry, they turn brown and pop open.
The leaves of the Catawba are the sole larval food source of one sphinx moth. The large caterpillars are excellent fishing bait and are known as "Catawba worms."