The name C. × erubescens covers the various hybrids that have arisen in cultivation between the American southern catalpa C. bignonioides and the Chinese C. ovata. The type plant was described by Carrière in Rev. Hort., 1869. It arose independently of ‘J. C. Teas’, but whether it was put into commerce is not known.
cv. ‘Hybrida’. – Described by Späth in 1898 from a plant growing in his arboretum. He did not claim to have originated it and it is usually assumed that the plant belonged to the clone ‘J. C. Teas’.
cv. ‘J. C. Teas’. – This – the best-known form of the cross – was raised by J. C. Teas at Bayville, Indiana, U.S.A. around 1874, from seed of C. ovata. The seed parent grew in the proximity of both C. speciosa and C. bignonioides, but it is now accepted that the pollen came from the latter species and not from C. speciosa, as stated in previous editions. The unfolding leaves are purplish, broad-ovate or slightly three-lobed, cordate, up to 12 in. long, downy beneath. Flowers white, stained with yellow and minutely spotted with purple, smaller than in C. bignonioides, but more numerous. In the central United States it has shown an extraordinary vigour: leaves over 2 ft wide, and panicles carrying over 300 flowers, have been produced. In Britain it is decidedly inferior to C. bignonioides as a flowering tree; the leaves, however, even here, are the largest in the genus. It flowers about the end of July into August and was introduced in 1891.
Large specimens of this hybrid recorded recently are: Hergest Croft, Heref., 58 × 73⁄4 ft (1963); Wakehurst Place, Sussex, 62 × 43⁄4 ft (1964); Crowholt, Farnham, Surrey, 50 × 81⁄2 ft (1963); Syon Park, Middx., 58 × 73⁄4 ft (1968).
cv. ‘Japonica’. – This plant was put into commerce by Simon-Louis Frères about 1886. It was said to have come from Japan and was described by Dode as a species – C. japonica. However, it is considered by Paclt (Candollea, 1952) to be a form of C. × erubescens and thus presumably of European garden origin. It is distinguished from C. ovata by its narrower, more compact and pyramidal inflorescence and its less markedly lobed leaves, of a clearer, more glossy green, and less downy. The flowers are fragrant, of a purer white than in C. ovata, dotted inside with violet. This is a vigorous and quick-growing tree.
cv. ‘Purpurea’. – Leaves and young shoots dark purple, almost black, when quite young. The colour largely disappears with age from the leaf-blade, but it always remains darker than in the type; the leaf-stalks retain it. This tree has long been considered a form of C. ovata, but is referred by Paclt to C. × erubescens. Its origin is uncertain, but it was probably raised in the Meehan nurseries near Philadelphia, U.S.A., before 1886. There is a fine specimen in the University Botanic Garden, Cambridge.