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Alasdair and Panny Laing
Tom Clark (2023)
Clark, T. (2023), 'Enkianthus serrulatus' from the website Trees and Shrubs Online (treesandshrubsonline.
Shrubs or small trees, deciduous, 3–6 m tall. Twigs glabrous. Leaf petiole 6–10 mm, glabrous or sparsely hispidulous; leaf blade elliptic, oblong-elliptic, or obovate-elliptic, 5–8 × 1.6–2.6 cm, papery, both surfaces hispidulous or glabrous, or abaxially densely floccose toward base and adaxially glabrous, midvein strongly raised abaxially, flat to slightly raised adaxially, secondary and fine veins slightly raised abaxially, inconspicuous adaxially, base broadly cuneate to narrowly obtuse, margin denticulate, apex shortly acuminate. Inflorescence umbellate, 2–6-flowered. Pedicel 1–2 cm, glabrous or pubescent. Calyx lobes triangular, c. 2.2 mm, glabrous or ciliate. Corolla white, campanulate, c. 1 cm; lobes recurved. Filaments pubescent. Ovary glabrous or pubescent; style glabrous. Capsule 5-angled, 7–10 mm; stalk erect, 2–3 cm. Flowering April, fruiting May–October. (Ruizheng & Stevens 2005).
Distribution China Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangxi, Sichuan, Yunnan, Zhejiang Vietnam
Habitat Forest margins, mountain slopes, roadsides; 800–1800 m asl.
USDA Hardiness Zone 6-7
Conservation status Not evaluated (NE)
Ernest Henry Wilson (1876–1930), during his first expedition on behalf of Messrs. Veitch, collected the type specimen of Enkianthus serrulatus in April 1900 in a ravine south of Ichang, western Hubei. In describing it, Wilson assigned it to varietal status under E. quinqueflorus, underscoring their close relationship, but eleven years later this taxon was elevated to species rank by the German botanist Camillo Karl Schneider (1876–1951). Bean differentiates E. serrulatus as being quite deciduous, with the leaves being less leathery and very finely toothed; having glabrous young shoots; bearing bud scales that are minutely ciliate; and having pure white flowers (Bean 1981).
E. serrulatus was introduced to cultivation in the United Kingdom in 1900 but despite the fact that it has amongst the largest flowers in the genus it is still today only sporadically encountered in gardens. This is a pity as it is a lovely and striking plant blooming relatively early in the season, before the leaves or just as the leaves emerge, not unlike the character of E. perulatus. E. serrulatus is grown at Benmore Botanic Garden in western Scotland (Royal Botanic Garden Edinburgh 2022) but is sparsely distributed elsewhere in the UK and Europe, generally. This species is encountered with slightly greater frequency in the United States, mostly from material of cultivated origin but some plants of wild origin can be found at the Rhododendron Species Botanical Garden near Seattle, Washington and at Sonoma Botanical Garden (formerly Quarryhill Botanical Garden) near San Francisco. Both of these institutions have considerable collections of Enkianthus and the latter has one of the best collections of wild-sourced Enkianthus in the world in terms of both taxonomic and genetic diversity. Steve Hootman, director of the Rhododendron Species Botanical Garden near Seattle, Washington, has travelled, explored and collected extensively in China and has frequently encountered this species. He writes of it based on a 2018 trip to Yunnan and Sichuan stating that “it is the common low-elevation species in central and southern China, and is easily distinguished by its very early, pure white flowers…the foliage turns bright red in the Fall” (Hootman 2020). In the UK yellow is the more typical autumn colour (R. White pers. comm. 2023). Michael Dirr muses that “perhaps a breeder could work miracles with this large-flowered species and the rich pink, rose and red” flowers of other species (Dirr 2009). Indeed, perhaps selective breeding could introduce a modicum of cold hardiness, as well, as that seems to be one factor accounting for its limited occurrence in cultivation.