Cotoneaster divaricatus
Cotoneaster divaricatus Rehder & E.H. Wilson in Sargent, Pl. Wilson. 1(2): 157, 1912.
Section Adpressi, Series Horizontales
Origin: Central and Southwest China.
Presence in western Europe: Naturalized in France (Farille & al. 2010), Germany (Dickoré & Kasperek 2010) and Great Britain (Stace 2010). Also known from Scandinavia (Karlsson 2002).
Cultivation in Belgium and the Netherlands: “common” (De Koning & van den Broek 2009).
Comparative taxonomy: Species accepted by Lingdi & Brach (2003) and Dickoré & Kasperek (2010).
Illustrations: Palmer (1983), Macpherson & Lindsay (1993), Hylmö (1993), Grevtsova (1999), Henker & Kiesewetter (2006), De Koning & van den Broek (2009), Fryer & Hylmö (2009), Stace (2010). See also: http://www.british-wild-flowers.co.uk/C-Flowers/Cotoneaster,%20Spreading.htm.
Apparently first collected in Belgium in coastal dunes in Koksijde (Oostduinkerke) in 2001. In this area Cotoneaster divaricatus now has become a more or less widespread exotic shrub although it rarely occurs in dense stands. It is very likely that it was already present (but neglected) long before 2001. It now occurs in numerous coastal areas, especially between De Panne and Nieuwpoort, often in nature reserves (for instance: Doornpanne, Fluithoekduinen, Noordduinen, Plaatsduinen, Ter Yde, …). Elsewhere along the Belgian coast Cotoneaster divaricatus appears to be less widespread. It was recorded, for instance, in Raversijde in 2003. In inland localities it is much rarer, although it is locally naturalized in abundance in Antwerpen-Linkeroever (Sint-Anna). Exceptionally seen elsewhere and probably often rather ephemeral, for instance on the verge of an abandoned quarry near Lessines in 2010.
Cotoneaster divaricatus predominantly occurs on calcareous, dry, sandy soils, in either natural (coastal dunes) or artificial (sand raised sites) habitats. It is furthermore sometimes seen on calcareous rocks (former quarries) and always grows in full sun or half shade. In Central Europe – where it is one of the most widespread and common representatives of the genus (Dickoré & Kasperek 2010) – it seems to occur in a much wider range of habitats (urban waste land, scrub, dry grassland, forest margins or clearings). In Halle (Germany) Cotoneaster divaricatus is considered to be an invasive species, especially under Pinus and in clearings.
Cotoneaster divaricatus is a very characteristic species in fruit: its fruits are cylindrical (at least twice as long as wide and with parallel sides). In the absence of fruits it is likely to be confused with other species, especially Cotoneaster simonsii and even with vigorous shrubs of C. horizontalis (or, more likely, C. ascendens). These three species are opposed in the tables here under:
|
Cotoneaster divaricatus |
C. simonsii |
|
Branches spreading |
Branches stiffly erect (very typical!) |
|
Fruit cylindrical, dark red to ruby red |
Fruit obovoid, bright orange to orange red |
|
Leaves chartaceous, 10-30 mm long, rather sparsely strigose initially |
Leaves chartaceous to (more often) subcoriaceous, 19-33 mm long, rather densely strigose initially |
|
Nutlets usually 2 per berry |
Nutlets usually 3 (rarely 2 or 4) per berry |
|
Cotoneaster divaricatus |
C. horizontalis / C. ascendens |
|
Branches spreading, branchlets divaricate |
Branches decumbent – ascending, branchlets strongly distichous |
|
Fruit cylindrical |
Fruit subglobose |
 |
 |
 |
 |
 |
Literature
De Koning J. & van den Broek J.W. (2009) Nederlandse Dendrologie (14e druk, geheel herzien). 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).
Farille M.A., Zeller J., Jordan D., Charpin A. & Garraud L. (2010) Cotonéasters échappés de jardins en Haute-Savoie. Monde Pl. 501: 1-5.
Fryer J. & Hylmö B. (2009) Cotoneasters. A comprehensive guide to shrubs for flowers, fruit, and foliage. Timber Press, Portland-London: 344 p.
Grevtsova A.T. (1999) Atlas Cotoneasters. Cotoneaster (Medic.) Bauhin. Kiev, House Orchard, Truck-Garden: 372 p.
Henker H. & Kiesewetter H. (2006) Erstnachweise kritischer Pflanzensippen für Mecklenburg-Vorpommern (Blütenpflanzen). Bot. Rundbr. Mecklenburg-Vorpommern 41: 5-20.
Hylmö B. (1993) Oxbär, Cotoneaster, i Sverige. Svensk Bot. Tidskr. 87: 305-330.
John H. & Frank D. (2008) Verwilderte Cotoneaster-Arten in Halle (Saale) und Umgebung. Mitt. Florist. Kart.Sachsen-Anhalt 13: 3–28 [available online at: http://www.bv-st.de/images/Flo-Kart_2008_003-028_John_Frank.pdf).
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].
Macpherson P. & Lindsay E.L.S. (1993) Cotoneasters in the Glasgow Section of V.C. 77. Glasg. Nat. 22(2): 111-114.
Palmer J.R. (1983) An overlooked Cotoneaster. BSBI News 34: 27-28.
Stace C. (2010) New Flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.