Cornus oblonga Wall.

The evergreen Cornus oblonga has the peculiarity of flowering from autumn into mid-winter, when its large corymbs of white flowers are advantageously displayed above the foliage, providing useful forage for late-flying insects; the fruits mature and are dispersed in spring. The evergreen habit and unusual phenology are anomalous features attributable to the species’ position in an early-diverging lineage of the blue-fruited dogwoods (subgenus Yinquania), which consists of just three species, the others being the evergreen C. peruviana from tropical South America and (according to recent findings) the Chinese C. parviflora (Du et al. 2023). Together these constitute the small subgenus Yinquania, distinguished from the rest of the blue-fruited dogwoods by persistent inflorescence bracts, which often remain attached until flowering (Xiang & Boufford 2005). Also unusual are the species’ 3– or 4-locular fruits (all other species being 2-locular), which are congruent with its posited basal position in the lineage: the higher locule number reflects what appears to be the plesiomorphic condition observed in fossil Cornus taxa (Eyde 1988). The Paleocene C. piggae Manchester, Xiang & Xiang has 2–3 locules, and the Eocene species C. multilocularis Gardner (Eyde) and C. ettingshausenii are seen to have 3–6 and 3–5 locules respectively (Atkinson, Stockey & Rothwell 2016); it is worth noting, however, that one of the fossil species cited by Eyde (1988) – Cornus quadrilocularis Chandler, from English mid to late Eocene deposits (c. 45 Ma) – has since been referred to Curtisia, also in the Cornales (Manchester, Xiang & Xiang 2007). While competition among autumn-fruiting Cornus appears to have favoured the evolution of more efficient 2-seeded fruits, Eyde proposes that the unconventional phenology of C. oblonga (though perhaps an innovation in itself) is a key factor in its retention of the ancestral plurilocular condition, since it did not expose the species to the selection pressures operative in the spring- and summer-flowering guilds.

Cornus oblonga has a very wide distribution in Asia, having been first encountered by Western botanists in northern India, from which it was described by Wallich (Roxburgh & Wallich 1820). Loudon (1838) noted its purported introduction in 1818, but stated that he had never seen it. Later in the century, Augustine Henry collected the species on several occasions (Henry 9930, 11161 and 11397), and it was being grown by Vilmorin at Les Barres in 1904 (Vilmorin & Bois 1904). Bean described his specimen of the plant in 1921 from a plant growing at Wakehurst Place, Sussex, originally received from the Veitch nursery at Coombe Wood in 1913 – this plant was probably introduced from collections made by E. H. Wilson on the firm’s behalf (Bean 1976).

Numerous collections were also made by Forrest in Yunnan between 1904 and 1921, though it has not been possible to connect any of these to cultivated plants. In fact, given the species’ wide natural range, and the frequency with which it was recorded by botanists and other travellers, there are surprisingly few records of its actually having been introduced – perhaps its appearance and phenology gave the impression that it would not be hardy. Even today Cornus oblonga remains rare in cultivation, found in only a handful of botanical collections, though it is offered by a small number of European nurseries. In Britain, it is represented mainly by material collected in Western Yunnan in 1990 by Howick & McNamara (H&M 1556). At the Sir Harold Hillier Gardens plants have formed attractive shrubs, flowering from late autumn to early spring.

Though not bone-hardy in the British climate, as a winter-flowering broadleaf evergreen, Cornus oblonga lends itself well to planting in urban and suburban situations, fully warranting its rather unexpected listing in Peter Bridgeman’s generalist planting guide (1979). Branches may be killed by frost (perhaps at only –5°C, but probably lower), but the plant can regenerate from the main stems (Gayraud 2013). Plants at the Arboretum Cimetière Parc, Nantes are reported to bear –5°C without damage (J. Garnett pers. comm. 2025).

The black fruits are the source of an industrial oil in Pakistan (Gayraud 2013); other plant parts are used in Asian medicine (Plants for a Future 2021).