Cornus hongkongensis Hemsl.

Six subspecies are recognised within this variable taxon, differing in details of pubescence and distribution. It is not entirely clear whether many of these are in cultivation, but Flora of China has a useful key, an adapted version of which is provided below.

Plants labelled Cornus hongkongensis are found occasionally in botanical gardens and other collections throughout our area, but few have been identified to subspecific level. In the United Kingdom subsp. melanotricha has been confirmed in cultivation, with trees from a collection by Mikinori Ogisu (Ogisu 94322) made in Sichuan in 1994 growing both at Kew and at the Sir Harold Hillier Gardens. The specimen from which our line drawing was made (Figure 27, p. 262) is a thriving small tree of about 3 m tall at the Hillier Gardens, from which stems were collected in sweltering heat in July 2006, conditions more enjoyed by the plant than by the author. This specimen also appears to fit best within the concept of subsp. melanotricha, recognised by the small tufts of hairs in the vein axils on the otherwise almost totally glabrous leaf undersides. It was obtained by Roy Lancaster from the Shanghai Botanic Garden in 1987, as C. kousa var. angustata – demonstrating the confusion over the identities of this group. A very attractive feature is the bronzy young foliage (A. Coombes, pers. comm. 2007). Recent collections from northern Vietnam are now available from Crûg Farm nursery in the United Kingdom: HWJ 1033 is identified only as C. hongkongensis, and HWJ 1022 as aff. tonkinensis. Confirmation will be required as these plants come into flower, as both subsp. gigantea and subsp. tonkinensis are recorded from this area.

Hot summers seem to benefit the Hillier tree, which was flowering prolifically when observed in 2006, although it has yet to set fruit (A. Coombes, pers. comm. 2007). (In 2007 it flowered even more prolifically, with larger bracts, due to the abundant moisture that year.) Hogan (2008) also suggests that C. hongkongensis will be particularly useful in hot climates. The ‘flowers’ are not large by comparison with other species, but they look well over the dark evergreen foliage and the species is much more than just a botanical curiosity, deserving cultivation in suitable sites.

The name Cornus capitata subsp. emeiensis (W.P. Fang & Y.T. Hsieh) Q.Y. Xiang, derived from Emei Shan, is not recognised by Flora of China, but in horticulture emeiensis appears in a diversity of orthographic variants (for example, omeiense) and taxonomic combinations in connection with a number of evergreen dogwoods – particularly in North America but increasingly in Europe as well. In North America, ‘C. omeiense’ became known through the release in 1990 by Piroche Plants of a seed-raised batch of plants named ‘Summer Passion’. It is important to note that these were not a uniform cultivar (although still sold as such by Piroche) and that there is considerable variation between so-named specimens (Hogan 2008). The situation is further confused in that there is a suggestion that these are intermediates between C. capitata and C. elliptica (Wharton et al. 2005). However, these plants tend to have characteristics that identify them with C. hongkongensis rather than C. capitata or C. elliptica, notably the glossy upper surfaces of the leaves and the more or less glabrous, smooth-feeling lower leaf surfaces. Without examining material from a wide range of trees it is impossible to assert that all trees in cultivation as C. emeiensis or ‘Summer Passion’ are indeed C. hongkongensis, and if so, identify the subspecies to which they belong: readers should investigate for themselves. Whatever the true affinities of these trees in cultivation, however, they are usually very attractive, with dark glossy leaves that flush red, and abundant flowers. They seem to be hardy in much of southern England, western North America and the milder areas of the East Coast. One small specimen was seen flowering prolifically at the JC Raulston Arboretum in May 2006.