northern catalpa

Catalpa speciosa is a medium-sized, deciduous tree growing to 15–30 meters (49–98 ft) tall and 12 meters (39 ft) wide. It has a trunk up to 1 meter (3 ft 3 in) in diameter, with brown to gray flaky bark. The leaves are deciduous, opposite (or whorled), large, heart shaped, 18–30 cm (7.1–11.8 in) long and 13–21 cm (5.1–8.3 in) broad, pointed at the tip and softly hairy beneath. The leaves generally do not color in autumn before falling; instead, they either fall abruptly after the first hard freeze, or turn a slightly yellow-brown before dropping off. The catalpa tree is the last tree to grow leaves in the spring. The winter twigs of northern catalpa are like those of few other trees, having sunken leaf scars that resemble suction cups. Their whorled arrangement (three scars per node) around the twigs is another diagnostic. The flowers are 3–6 cm (1.2–2.4 in) across, trumpet shaped, white with yellow stripes and purple spots inside; they grow in panicles of 10–30. The fruit is a long, thin legume-like capsule, 20–40 cm (7.9–15.7 in) long and 10–12 mm (0.39–0.47 in) in diameter; it turns brown in the fall and often stays attached to tree during winter (and can be mistaken for brown icicles). …

Catalpa speciosa was originally thought to be native only to a small area of the midwestern United States near the confluence of the Mississippi and Ohio Rivers. However, in 1976, investigation of an archeological site of an island in West Virginia's portion of the Ohio River revealed Catalpa speciosa to be present on the island around the period of 1500-1700 CE. This suggests that Catalpa speciosa may have experienced a decline in range before European settlement. Today, its range has widely expanded east of the Rocky Mountains outside of its restricted pre-settlement location, further obscuring its true native range.

It is widely planted as an ornamental tree. It is adapted to moist, high pH soil and full sun, but has been able to grow almost anywhere in North America. In the UK it has gained the Royal Horticultural Society's Award of Garden Merit (confirmed 2017). The wood is soft, like white pine, and light, weighing only 26 pounds per cubic foot when dry. It also does not rot easily; in earlier years it was used for fence posts and less than successfully as railroad ties. More modern uses that highlight the wood's beautiful grain include furniture, interior trim and cabinetry. Catalpa has one of the lowest shrinkage/expansion rates of any U.S. hardwood. Only northern white cedar and redwood have lower shrinkage/expansion rates, and not by much. The wood's unique properties make it excellent for carving and boatbuilding. Often regarded as a weed tree, its wood is under-appreciated and underused. The tree's tendency to grow crooked does not help its reputation as a source of usable lumber. Northern catalpa has been extensively cultivated in Ohio for over 200 years, and is now naturalized in urban and rural areas. Farmers introduced the rapidly growing northern catalpa to Ohio to produce large amounts of timber for fenceposts. Three liabilities exist in urban areas where it is found as both a shade and an ornamental tree. …