Cornus walteri Wangerin

A curiosity among subgen. Thelycrania for its tree-sized proportions, Cornus walteri is one of a handful of Cornus species capable of forming a substantial single trunk. The tree has other charms – glossy, mid- to dark-green leaves with undulating margins hang attractively from the branches, while large flat-topped white inflorescences are held above the foliage in spring – but it is the bole that is its most striking feature, the bark developing a remarkable deeply creviced texture likened to the ‘alligator-hide’ appearance of Diospyros virginiana (Wilson 1927; Lancaster 2008). Cornus walteri is often treated as including the Korean C. coreana, and the relationship between the Korean and Chinese species (or populations) is still undetermined. It may prove significant that the bark of C. coreana appears to develop a platy, mosaic-like condition not seen in C. walteri, though broader surveys and investigation are needed to better understand this character.

Jacobson (1996) described Cornus walteri as ‘extremely rare’ in cultivation, but this is an overstatement. The species has been available commercially on both sides of the Atlantic for decades (see e.g. United States Department of Agriculture 1995), and is found in many collections and even occasionally as a landscape tree. In Britain, numerous specimens are listed on the TROBI database, and the species was considered sufficiently familiar to merit full treatment in Allen Coombes’ generalist tree guide (Coombes 1992). In cultivation trees attain heights comparable with (or exceeding) those recorded in wild trees: in 2024 the measurements of the tallest British specimen, at Wakehurst Place, were 16.6 m tall, 104 cm girth; a 16 m tree grows at Castlewellan in Co. Down.

Cornus walteri was long grown under the misapplied name C. wilsoniana (see that entry), a species that is superficially similar in appearance, but which appears to occupy a more basal position in the subclade (Du et al. 2023). By contrast, Cornus walteri appears to be closely related to C. sanguinea – surprising, perhaps, in view of their difference in stature, though the kinship is borne out in other characters (indeed, early herbarium specimens of C. walteri are often labelled C. sanguinea).

According to Bean (1976), Cornus walteri was introduced into cultivation by Wilson in 1907 under Wilson 1017, though Bean must be mistaken about the year, since that collection (from Wenchwan-Hsien, western Sichuan) was not made until 1908 – indeed no seed collection by Wilson appears to have been made prior to June 1907 (Rehder, in Sargent 1916). Wilson 1071 was made generally available in the United States in 1912 under PI 34566; clonal material from W 1017 is offered in Britain by Exclusive Plants (2026). Joseph Hers collected the species (‘sha liang’ or ‘mao liang’) in North Hunan in 1919 (Hers 946), sending seeds to the Arnold Arboretum, introduced under PI 50410 (Hers 1922; Bulletin de la Société dendrologique de France 1922). Another American introduction (ultimate provenance unknown) was made in 1921 as cuttings acquired from Vilmorin-Andrieux, Paris under PI 52702. Some decades later, material derived from another Wilson collection, Wilson 375 from western Hubei, was imported to North America from Les Barres Arboretum, France, under PI 261268 by Frederick Meyer (Meyer 1963). In the United Kingdom, the tree was being offered by Hilliers by the mid 1930s: the 15 m tree at the Hammond Arboretum, Leicestershire (blown over in 2018) was purchased from there in 1934 (Hammond Arboretum 2025). Recent introductions include BSWJ 8776 from Crûg Farm.

The species’ natural habitat is not wholly clear, and the agricultural or semi-natural contexts in which explorers encountered many woody species may give a skewed picture of their actual distribution; however, collectors often encountered Cornus walteri on open hillsides. Photographs taken by Wilson in May 1910 include two images of medium-sized (9 m) specimens in full flower, one with a full crown and spreading habit on the edge of woodland near Xingshan County (Hsing-shan Hsien) at 1200 m asl (O-73). The other, growing on a steep, sparsely wooded slope in northwest Ichang at 915 m asl, has a narrower, ascending crown (O-17). Cornus yunnanensis was described from the banks of the Yangtze (Li 1944).

Cornus walteri is commercially planted as a source of cooking oil (Richardson 1990), and as a shade tree in urban situations. A leaf-mining moth, Antispila sinensis Hübner, has been reported to damage foliage in China (Liu & Wang 2017). Dirr and Heuser (1987) report the species as difficult to raise from seed and hard to root from cuttings.