Northern Catalpa — Catalpa speciosa
Catalpa is the Cherokee Indian name for the tree, adopted by early settlers; speciosa is Latin meaning ornamental. Variously known as Catalpa, Indian Bean, Cigar Tree and Catawba this tree is valued for fence posts since its timber will lie on wet ground for a century and still not rot. It is native only to North America.
The large, almost heart-shaped leaves of this species and the long cigar-shaped fruiting capsules make this tree easy to identify even from a distance. Even though Catalpa is hardy at lower elevations in Colorado, it should be considered borderline and subject to occasional setbacks in years of prolonged subzero cold.
Its native habitat is in the bottomland soils of southern Indiana, southeastern Missouri and into Kentucky and Tennessee. In other states, it has become naturalized from plantings by man. The typical growth habit is narrow columnar and, in winter, is a picturesque specimen due to the stout, rugged branches and persistent cigar-like capsules.
Even though the tree tends to be brittle, it is rarely caught in late spring or early fall snows with the foliage still on, thus escaping severe storm damage.
Other Denver locations
Planted widely in the area, a good specimen is located at South High School.
http://en.wikipedia.org/wiki/Northern_Catalpa

