Cotoneaster Cotoneasters

A large genus of mainly Asiatic species many of which have been introduced as garden plants and have escaped and become naturalised in Britain. Clive Stace describes 93 species in the 4th edition of New Flora of the British Isles (2019) making it one of our largest genera. Many species flower profusely in the wild and are very attractive to pollinators, particularly bees. Fruit production is often prolific and frugiverous birds such as thrushes play a significant role in consuming the berries and dispersing seed. Most of the species in the British Flora are polyploids (triploid, tetraploid or hexaploid) and apomictic. Diploid species are all 2n=34 and usually outbreeding.

Identification of Cotoneasters is difficult and misidentification is common. There are useful aids, the most authoratative  of which is the monograph, Cotoneasters, by Jeanette Fryer and Bertil Hylmo (2009) which has detailed keys, descriptions and photographs. Stace's flora provides multi-access and general keys and descriptions while John Poland and Eric Clement provide a very useful set of keys to some of the most common species in The Vegetative Key to the British Flora (2nd edition, 2020). Some of the most commonly encountered Cotoneasters in West Glamorgan include: Cotoneaster horrizontalis, Cotoneaster integrifolius, Cotoneaster lacteus, Cotoneaster rehderi, Cotoneaster salicifolius, Cotoneaster simonsii and Cotoneaster sternianus.

Of the species which have been recorded in West Glamorgan, Cotoneaster sheriffii and Cotoneater thymifolius are not described here.

All but one of the cotoneaster species in the British Flora are neophyte aliens, some of which are significant invasive species. The only native cotoneaster species in the British Flora is Wild Cotoneaster (Cotoneaster cambricus), which occurs in a small population on the limestone of Great Orme Head, north Wales. It does not occur in south Wales.