In this new series of blogs, I hope to condense the available information associated with different groupings of cotoneasters. This will include wild and naturalised species but also some available in horticulture and thus, likely to occur in the future. References are provided.
Medium shrubs to small trees with subcoriaceous leaves boasting a strongly bullate [blistered] upper surface and often, deeply impressed veins. Most fall into series Bullati (Flinck & B. Hylmö) but several other superficially similar species known to occur are also included.
Of these cotoneasters, only Hollyberry Cotoeaster (Cotoneaster bullatus) and Bullate Cotoneaster (Cotoneaster rehderi) are known to occur widely in the UK and are often confused. Several other species, most notably Bois’s Cotoneaster (Cotoneaster boisianus) and Firebird Cotoneaster (Cotoneaster ignescens) are known to occur more scantly but may have been overlooked. More species still are available in horticulture and grown in botanical gardens and arboretums and as such, as liable to occur in the future.
Fruits Red
| C. bullatus | C. rehderi | C. obscurus | |
| Fruit | Globose or obovoid, 7-8mm, rich red, shiny, glabrescent, calyx lobes depressed; nutlets 5 (rarely 4). | Globose or depressed globose, 8-11mm, bright red, shiny, calyx lobes flat; nutlets 4-5. | Obovoid, 7-9mm, red to maroon, shiny, glabrous, calyx lobes flat; nutlets 3-4. |
| Flowers | 12-30 flowered. Corolla closed or with small opening, petals red and pale pink with a greenish pink border; filaments pale pink, anthers white. | 10-30 flowered. Corolla closed, petals red or maroon with pink border; filaments pink, anthers white. | 7-12 flowered. Corolla closed, petals pink and greenish white with some red; filaments red and pink, anthers white. |
| Leaf size | 55-90mm x 26-46mm | 70-210mm x 45-90mm | 25-45mm x 12-28mm |
| Leaf above | Bullate, initially reddish brown, shiny, initially pilose; veins 6-9 impressed. | Strongly bullate, mid-green, shiny, slightly pilose, veins 8-11 impressed. | Bullate, dark green, slightly shiny, initially strigose; veins 3-5 impressed. |
| Leaf below | Villous, especially on midrib. | Lightly green, initially yellowish strigose. | Somewhat reticulate, yellowish tomentose-villous. |
| Branchlets | Maroon, initially yellowish pilose | Maroon and lenticellate, initially pilose. | Maroon, initially yellowish pilose |
| UK Status | 2388 records (Sept 2024) | 3612 records (Sept 2024) | 10 records (Sept 2024) |
| Comment | Common in some parts | Perhaps the most likely species to be found in all habitats across the UK. | Rather unlikely |
Similar Species in Cultivation
Cotoneaster emeiensis has large leaves reminiscent of C. rehderi (120-160mm x 55-60mm) and could be easily confused. It has slightly smaller fruits (8-9mm) and it’s flowers differ with petals that are red with a brownish-red base and a pink border. It is now available for sale in the UK, and has been planted at select botanical gardens.
Cotoneaster ataensis has smaller leaves than the species above (35-50mm x 25-33mm) but shares the rich red fruits. It differs in having 3-9 flowers, each with an open corolla and petals which are red with a blackish-purple base and a pink border. Fryer & Hylmö (2009) state that this species is widespread in cultivation but often mislabelled as C. bullatus.
Cotoneaster atuntzensis could be mistaken for either C. bullatus or C. rehderi. It has shortly obovoid fruits (8-9mm) with 3-4 nutlets and petals which are pale pink and greenish with an off white border.
© lern via iRecord
Fruits Orange-red to Orange
| C. ignescens | C. boisianus | C. sikangensis | |
| Fruit | Obovoid or depressed globose, 9-10mm, orange-red, shiny, sparsely pilose, calyx lobes flat; nutlets 3-4. | Obovoid, 9-11mm, orange-red, base pilose, calyx lobes flat; nutlets 4-5. | Obovoid, 9-11mm, orange-red, subglabrous, calyx lobes flat; nutlets 3-5 (mostly 5). |
| Flowers | 3-13 flowered. Corolla with small opening, petals reddish brown with a pink or off-white border; filaments red and pink, anthers white. | 9-18 flowered. Corolla closed, petals red with a dark red base and pale pink border; filaments red and pink, anthers white. | 3-15 flowered. Corolla closed or with small opening, petals pink with greenish brown or white stripe, border off-white; filaments pale pink, anthers white. |
| Leaf size | 38-50mm x 23-28mm (subcoriaceous) | 46-60mm x 22-32mm (chartaceous) | 26-40mm x 13-24mm (subcoriaceous) |
| Leaf above | Bullate, dark green, shiny, strigose; veins 5-7 impressed. | Slightly bullate, dark green, dull, pilose-strigose; veins 6-8 impressed. | Bullate, dark green, shiny, pilose-strigose; veins 4-6 impressed. |
| Leaf below | Densely whitish pilose-villous | Reticulate, yellowish pilose. | Densely villous-pilose |
| Branchlets | Maroon, initially pilose-strigose. | Maroon, strigose-pilose. | Maroon, initially yellowish pilose |
| UK Status | 9 records (Sept 2024) | 36 records (Sept 2024) | Not yet recorded |
| Comment | Highly unlikely | Grows easily from seed in my experience so perhaps one to hunt for! | Apparently available in horticulture |
via Manual of the Alien Plants of Belgium
via Manual of the Alien Plants of Belgium
References
- Dickoré, W.B. & Kasperek, G. (2010). Species of Cotoneaster (Rosaceae, Maloideae) indigenous to, naturalising or commonly cultivated in Central Europe. Willdenowia 40: 13-45
- Verloove, Filip. (2014). Het genus Cotoneaster in België. Dumortiera. 103. 3-29.
- Fryer, J.; Hylmö, B. (2009). Cotoneasters: a comprehensive guide to shrubs for flowers, fruit, and foliage. Timber Press, Portland.
- Verloove F. (2024). Manual of the Alien Plants of Belgium. Botanic Garden Meise, Belgium.