Cotoneaster zabelii C.K. Schneider, Illustr. Handb. Laubholzk. 1: 749, 1906.
Section Cotoneaster, series Zabelioides.
Origin: China (Shaanxi).
Presence in western Europe: Naturalized in Great Britain (Stace 2010). Also known from Germany (John & Frank 2008; Dickoré & Kasperek 2010).
Cultivation in Belgium and the Netherlands: “rare” (de Koning & van den Broek 2009). Cotoneaster zabelii in cultivation probably includes C. fangianus, the latter being predominant.
Comparative taxonomy: C. zabelii is accepted by both Lingdi & Brach (2003) and Dickoré & Kasperek (2010).
Illustrations: Grevtsova (1999), Roloff & Bärtels (2006), John & Frank (2008), de Koning & van den Broek (2009), Fryer & Hylmö (2009), Stace (2010).
At present Cotoneaster zabelii is known from two localities in Belgium. One is in coastal woodland in Knokke. Previous claims from the seadunes all proved to belong with the related (and apparently much more frequently cultivated) Cotoneaster fangianus. Cotoneaster zabelii also grows in an abandoned gravel pit near Mons (Bois des Dames, Maisières). These plants were initially ascribed to native Cotoneaster integerrimus.
The separation of Cotoneaster fangianus and C. zabelii is rarely straightforward and identification keys in standard floras are often conflicting. Both have very characteristic long-pedicelled, pendent fruits and leaves that are rounded to acute at apex. They are readily distinguished from similar species like Cotoneaster dielsianus (with much shorter pedicelled fruits with 4 nutlets and abruptly acuminate leaf apex) and native C. integerrimus (with a subglabrous hypanthium and a fewer-flowered inflorescence). According to Fryer & Hylmö (2009), who studied the type specimens, Cotoneaster zabelii has slightly larger fruits (10-11 mm, versus 8-9 mm long), often at least some with 3 stones (versus 2). In addition leaves are usually slightly longer (32-40 mm, versus 21-35 mm long) and persist longer (deciduous by October in C. fangianus). Finally, petals always seem to be paler in Cotoneaster zabelii (usually pure white vs. pinkish in C. fangianus). The main differences between these two species are summarized in the table below.
|
C. zabelii |
C. fangianus |
|
Fruit 10-11 mm long |
Fruit 8-9 mm long |
|
Petals white |
Petals pinkish |
|
Usually three nutlets per berry |
Usually two nutlets per berry |
|
Leaves ca. 32-40 mm long |
Leaves ca. 21-35 mm long |
|
|
|
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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).
Fryer J. & Hylmö B. (2009) Cotoneasters. A comprehensive guide to shrubs for flowers, fruit, and foliage. Timber Press, Portland-London: 344 p.
Grevtsova A. (1999) Atlas Cotoneasters. Cotoneaster (Medic.) Bauhin. Kiev, House Orchard, Truck-Garden: 372 p.
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://bv-st.de/images/Flo-Kart_2008_003-028_John_Frank.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].
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.