Cotoneaster integrifolius

Cotoneaster integrifolius (Roxburgh) G. Klotz, Wiss. Z. Martin-Lutger Univ. Halle-Wittenberg, Math.-Naturwiss. 12: 779, 1963.

Synonym: Crataegus integrifolius Roxburgh.

Section Alpigeni, series Microphylli

Origin: Bhutan, India, Nepal.

Presence in western Europe: Naturalized in Great Britain (Stace 2010). Also known as an escape from cultivation in Austria and Germany (Dickoré & Kasperek 2010).

Cultivation in Belgium and the Netherlands: unknown; not accepted by De Koning & al. (2000). Possibly included in Cotoneaster microphyllus Wallich ex Lindley or, even more likely, in C. conspicuus J.B. Comber ex C. Marquand. Given as “rare” for Germany by Roloff & Bärtels (2006).

Comparative taxonomy: Species accepted by Dickoré & Kasperek (2010). However, these authors accept Cotoneaster integrifolius as a collective species that includes several other species from series Buxifolii, Conspicui, Microphylli and Radicantes. Lingdi & Brach (2003) still adopt another taxonomy: they subsume Cotoneaster integrifolius under C. microphyllus (as var. thymifolius (Baker) Koehne) (see also Klotz 1957).

Illustrations: Stace (2010).

Cotoneaster integrifolius is relatively easily distinguished from other escapes of the genus in Belgium. With its spreading, white petals, few-flowered inflorescences (nearly always a single flower), small evergreen leaves and decumbent stems confusion is only likely with Cotoneaster xsuecicus. Both are opposed in the table beneath.

Yet, Cotoneaster integrifolius is part of a difficult complex and much confused. From other related species it is best distinguished by the following characters: leaves at least twice as long as wide and (even the largest) less than 17 mm long, berry red and usually with 2 stones (rarely 3), flowers solitary (rarely paired), etc. This combination of features excludes most species that are known to occur as escapes (see Stace 2010) except Cotoneaster conspicuus and C. thymifolius Baker [1]. The latter is separated by its very tiny, subsessile leaves (rarely more than 7 mm long), smaller berries (3-6 mm vs. 7-9 mm) and smaller flowers (6-9 mm across vs. 7-15 mm across). Cotoneaster conspicuus, despite being a member of another series (Fryer & Hylmö 2009), is less easily distinguished. It has slightly larger (up to 20 mm long), less shiny and paler leaves and its berries are very shiny.

Cotoneaster integrifolius is probably relatively rare in cultivation in Belgium. Up to present it was recorded twice as an escape: a single shrub was recorded on the brick quay wall of river Leie in Kortrijk in 2001 and persisted for several years (now gone after demolition of the quay). In 2011 also discovered on top of an old cemetery wall in Menen (again a single specimen).

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Literature

De Koning J., Van den Broek J.W., Van de Laar H.J. & Fortgens G. (2000) Nederlandse dendrologie (13^e druk). H. Veenman & zonen, Ede: 585 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].

Klotz G. (1957) Übersicht über die in Kultur befindlichen Cotoneaster-Arten. Wiss. Z. Univ. Halle, Math.-Nat. 6(6): 945-982. 

Roloff A. & Bärtels A. (2006) Flora der Gehölze (2e Auflage). Ulmer, Stuttgart: 844 p.

Stace C. (2010) New Flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.