C. BUNGEI and C. KAEMPFERI, natives of China and Japan, are hardly to be relied upon, being of tender growth, and, unless in the most favoured situations, suffer from our severe winters. They resemble our commonly cultivated tree.
C. SPECIOSA.—United States, 1879. The Western Catalpa is more erect and taller of growth than C. bignonioides. The flowers too are larger, and of purer white, and with the throat markings of purple and yellow more distinct and not inclined to run into each other. Leaves large, heart-shaped, tapering to a point, of a light pleasing green and soft to the touch. It flowers earlier, and is more hardy than the former.
CEANOTHUS AMERICANUS.—New Jersey Tea. North America, 1713. A shrub of 4 feet in height, with deep green serrated leaves, that are 2 inches long and pubescent on the under sides. Flowers white, in axillary panicles, and produced in great abundance. This is one of the hardiest species, but succeeds best when afforded wall protection.
C. AZUREUS.—Mexico, 1818. This species, though not hardy enough for every situation, is yet sufficiently so to stand unharmed as a wall plant. It grows from 10 feet to 12 feet high, with deep-green leaves that are hoary on the under sides. The flowers, which are borne in large, axillary panicles, are bright blue, and produced in June and the following months. In a light, dry soil and sunny position this shrub does well as a wall plant, for which purpose it is one of the most ornamental. There are several good nursery forms, of which the following are amongst the best:—C. azureus Albert Pettitt, C. azureus albidus, C. azureus Arnddii, one of the best, C. azureus Gloire de Versailles, and C. azureus Marie Simon.
C. CUNEATUS (syn C. verrucosus).—California, 1848. This is another half-hardy species that requires wall protection, which may also be said of C. Veitchianus, one of the most beautiful of the family, with dense clusters of rich blue flowers and a neat habit of growth.
C. DENTATUS.—California, 1848. With deeply-toothed, shining-green leaves, and deep blue, abundantly-produced flowers, this is a well-known wall plant that succeeds in many parts of the country, particularly within the influence of the sea. It commences flowering in May, and frequently continues until frosts set in. It is a very desirable species, that in favoured situations will grow to fully 10 feet high, and with a spread laterally of nearly the same dimensions.
C. PAPILLOSUS.—California, 1848. This is a straggling bush, with small, blunt leaves, and panicles of pale blue flowers on long footstalks. A native of California and requiring wall protection.
C. RIGIDUS.—Another Californian species, is of upright, stiff growth, a sub-evergreen, with deep purple flowers produced in April and May.
There are other less hardy kinds, including C. floribundus, C. integerrimus, C. velutinus, and C. divaricatus.