Catalpa × galleana Dode

This hybrid was first described by Dode (1907), from a plant grown by Émile Gallé (1846–1904), in whose garden at La Garenne, Nancy, Dode probably first encountered it. A botanically trained polymath who achieved fame as an influential Art Nouveau glassmaker and designer, Gallé was an enthusiastic collector of East Asian plants and had a special interest in Catalpa. Though he died before he was able to complete a planned monograph on the genus, he had already assembled a representative collection of the various species, and had undertaken experiments in their hybridisation (Le Monnier 1904), of which Catalpa × galleana is one of the results. It appears that Gallé had been able to make progress on his monograph in the period before to his death; his notes survive, but have passed into private ownership (Le Tacon 2005). Gallé’s personal character – described by his obituarist Le Monnier (1904) as ‘a curious mélange of scientific precision and fantastical imagination’ – found expression not just in his practical horticultural trials, but also in the skill with which he combined botanical detail with elaborate decoration in his artistic designs.

It is possible that Dode visited Nancy only after Gallé’s death in 1904, since he was uncertain of the identity of one of the parents (the methodical Gallé would certainly have known). In the colour of the petioles and of the foliar nectaries the hybrid was unquestionably derived from C. ovata, and Dode found the leaves’ basal venation to be ‘reminiscent of C. cordifolia’, by which he meant C. speciosa (=C. cordifolia J.St.-Hil.) (Dode 1907) – this parentage was confirmed by Paclt (1952).

What became of Gallé’s hybrid is unknown. Paclt (1952) asserted that there was a specimen of C. × galleana growing at Plzeň, Czech Republic, though its provenance is not known. It is not impossible that Gallé’s original cross persists in the form of old trees – or perhaps their progeny (since other instances of the cross have proved fertile, see below) – in the environs of Nancy, where Gallé’s house still stands in its original garden. It is also possible that plants may have been grown at the Botanic Garden in Nancy, where Gallé was on the committee.

This cross was unknown in the United States until Karl Sax obtained a specimen from a controlled pollination in the 1930s; that plant is recorded as having seeded copiously in 1940 (Smith 1941). More recently, the cross has been recreated at the U.S. National Arboretum, as part of a strategy to increase the available genetic base for its breeding programme. The hybrid combines the hardiness of both species, with the larger flowers of C. speciosa and the greater mildew resistance of C. ovata. No cultivars are known, but it served as the pollen parent of ×Chitalpa ‘NCXC1’ El Niño^®.