Cotoneaster nanshan M. Vilmorin ex Mottet, Les arbres et arbustes d'ornement: 207, 1925.
Syn.: C. adpressus Bois var. praecox Bois & Berthault.
Section Adpressi, series Adpressi
Origin: China (Sichuan, Yunnan).
Presence in western Europe: Locally naturalized in the British Isles (Stace 2010). Also known from Scandinavia (Karlsson 2002).
Cultivation in Belgium and the Netherlands: "common" (De Koning & van den Broek 2009).
Comparative taxonomy: Most species of series Adpressi (incl. Cotoneaster nanshan) are reduced to synonymy under C. adpressus by Dickoré & Kasperek (2010). Despite being endemic to China Cotoneaster nanshan is omitted by Lingdi & Brach (2003) in Flora of China, not even as a synonym.
Illustrations: Grevtsova (1999), Fryer & Hylmö (2009), Stace (2010).
Cotoneaster nanshan was discovered on a dry and sun-exposed grassy bank of river Schelde south of Antwerpen in 2010 (a single individual). This record was initially ascribed to Cotoneaster beimashanensis J. Fryer & B. Hylmö by J. Fryer, based on a fruiting specimen only.
Compared with the species known so far to occur in the wild in Belgium Cotoneaster nanshan is most reminiscent of C. ascendens or, much less likely, C. horizontalis. With the former it shares the more ascending habit with indistinct or absent herringbone pattern and the larger leaves (13-20 x 8-15 mm). However, it is separated from it by its leaves with undulate margins, its much larger berries (10-13 mm, versus 7-8 mm), often with only 1 or 2 nutlets (versus 2-3 in Cotoneaster ascendens). Moreover, its flowers are strikingly rose-pink and the upper leaf surface matt (in Cotoneaster ascendens, in contrast, flowers are pinkish white and the upper leaf surface shiny).
Literature
De Koning J. & van Den Broek (2009) Nederlandse Dendrologie (14th ed.). K.N.N.V.: 547 p.
Dickoré W.B. & Kasperek G. (2010) Species of Cotoneaster (Rosaceae, Maloideae) indigenous to, naturalising or commonly cultivated in Central Europe. Willdenowia 40: 13-45 [available online at: http://user.uni-frankfurt.de/~kasperek/papers/dickore_kasperek_2010.pdf].
Grevtsova A.T. (1999) Atlas Cotoneasters. Cotoneaster (Medic.) Bauhin. Kiev, House Orchard, Truck-Garden: 372 p.
Fryer J. & Hylmö B. (2009) Cotoneasters. A comprehensive guide to shrubs for flowers, fruit, and foliage. Timber Press, Portland-London: 344 p.
Karlsson T. (2002) Nyheter i den svenska kärlväxtfloran II. Korsblommiga–flockblommiga. Svensk Botanisk Tidskrift 96: 186-206. [available online at: http://sbf.c.se/www/pdf/96(3-4)/Karlsson.pdf]
Lingdi L. & Brach A.R. (2003) Cotoneaster. In: Wu Z.Y. & Raven P.H. (eds.), Flora of China, vol. 9. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 85-108 [available online at: http://flora.huh.harvard.edu/china/PDF/PDF09/Cotoneaster.PDF].