Catalpa, a genus of plants belonging to the natural order bignoniacew, whose generic characteristics are a two-parted calyx, a bell-shaped, swelling corolla, five stamens, two of which only are fertile, a long, slender, cylindrical pod, and broadly winged seeds. There are three species, all of them trees, with simple leaves and panicled, terminal flowers. The G. syringifolia (Loud.) is indigenous in the southern parts of the United States, and is cultivated as an ornamental tree in most of the cities of the northern states. It is distinguished by its silver-gray, slightly furrowed bark, its wide-spreading head, disproportioned in size to the diameter of its trunk, the fewness of its branches, and the fine pule green of its very large heart-shaped leaves. Its showy flowers are white, slightly tinged with violet, and dotted with purple and violet in the throat. They are succeeded by pods, often a foot in length, which hang till the next spring. In its natural locality, this tree frequently exceeds 50 ft. in height, with a trunk from 18 to 24 in. in diameter; but in Massachusetts it dwindles to a mere shrub, and is often killed by the frost.
It is cultivated in gardens in England, and on the continent of Europe. One of the oldest and largest catalpas in England is in Gray's Inn gardens, and is said to have been planted there by Lord Bacon. In parts of Italy and in the south of France the eatalpa is planted as a wayside tree, and along the avenues to country villas. It may be propagated either by seeds or from cuttings of the root. It usually reaches the height of 20 ft. in 10 years, soon after which it begins to blossom. The wood is light, of a very fine texture, susceptible of a brilliant polish, and often used in cabinet-making.