attractive habit and decorative fruit. Some cultivars are of known parentage, such as the very popular Cotoneaster × watereri Exell (Waterer's cotoneaster; C. frigidus × C. salicifolius), while others are of mixed or unknown heritage. The following species and cultivars have gained the Royal Horticultural Society's Award of Garden Merit:- Cotoneaster atropurpureus 'Variegatus' Cotoneaster conspicuus 'Decorus' Cotoneaster 'Cornubia' Cotoneaster lacteus Cotoneaster procumbens 'Queen of Carpets' Cotoneaster 'Rothschildianus' Cotoneaster salicifolius 'Gnom' Cotoneaster salicifolius 'Pink Champagne' Cotoneaster sternianus Cotoneaster × suecicus 'Coral Beauty' Cotoneaster × suecicus 'Juliette' Invasiveness Many species have escaped from cultivation and become invasive weeds where climatic conditions are suitable for them, such as the many Chinese species naturalised in northwestern Europe. C. glaucophyllus has become an invasive weed in Australia and California. C. simonsii is listed on the New Zealand National Pest Plant Accord preventing its sale and distribution because of its invasiveness. On Portland, Dorset, UK, it has become invasive and is regularly culled to prevent damage to the Jurassic Coast. Nomenclature and classification The genus name Cotoneaster derives from cotoneum, a Latin name for the quince, and the suffix -aster, 'resembling'. The name is correctly masculine, though in some older works it was wrongly treated as feminine, resulting in different name endings for many of the species (e.g.Cotoneaster integerrima instead of Cotoneaster integerrimus). The genus is often divided into two or more sections, though the situation is complicated by hybridisation: Cotoneaster sect. Cotoneaster (syn. sect. Orthopetalum). Flowers solitary or up to 6 together; petals forward-pointing, often tinged pink. Mostly smaller shrubs. Cotoneaster sect. Chaenopetalum. Flowers more than 20 together in corymbs; petals opening flat, creamy white. Mostly larger shrubs. Selected species Cotoneaster acuminatus Lindl. Cotoneaster acutifolius Turcz. – Peking cotoneaster Cotoneaster acutiusculus Pojark. Cotoneaster adpressus Bois – creeping cotoneaster Cotoneaster aestivalis (Walter) Wenz. Cotoneaster affinis Lindl. – purpleberry cotoneaster Cotoneaster afghanicus G.Klotz Cotoneaster aitchisoni C.K.Schneid. Cotoneaster alashanensis J.Fryer & B.Hylmö Cotoneaster alatavicus Popov Cotoneaster alaunicus Golitsin Cotoneaster albokermesinus J.Fryer & B.Hylmö Cotoneaster allanderi J.Fryer Cotoneaster allochrous Pojark. Cotoneaster altaicus J.Fryer & B.Hylmö Cotoneaster ambiguus Rehder & E.H.Wilson Cotoneaster amoenus E.H.Wilson – beautiful cotoneaster Cotoneaster amphigenus Chaten. Cotoneaster annapurnae J.Fryer & B.Hylmö Cotoneaster angustifolius Franch. Cotoneaster angustus (T.T.Yu) G.Klotz Cotoneaster antoninae Juz. & N.I.Orlova Cotoneaster apiculatus Rehder & E.H.Wilson – cranberry cotoneaster or apiculate cotoneaster Cotoneaster applanatus Duthie ex J.H.Veitch Cotoneaster arborescens Zabel. Cotoneaster arbusculus G.Klotz Cotoneaster argenteus G.Klotz Cotoneaster armenus Pojark. Cotoneaster arvernensis Gand. Cotoneaster ascendens