Cotoneaster Difficilis

''Cotoneaster'' is a genus of flowering plants in the rose family, Rosaceae, native to the Palaearctic region (temperate Asia, Europe, north Africa), with a strong concentration of diversity in the genus in the mountains of southwestern China and the Himalayas.Flora of China
''Cotoneaster''
(includes most of the world's ''Cotoneaster'' species) ''www.efloras.org'' They are related to hawthorns (''Crataegus''), firethorns (''Pyracantha''), photinias (''Photinia''), and rowans (''Sorbus'').

Depending on the species definition used, between 70 and 300 different species of ''Cotoneaster'' are described, with many apomictic microspecies treated as species by some authors, but only as varieties by others.Bean, W. J. (1976). ''Trees and Shrubs Hardy in the British Isles'' 8th edition. John Murray .

The majority of species are shrubs from tall, varying from ground-hugging prostrate plants to erect shrubs; a few, notably ''C. frigidus'', are small trees up to tall and trunk diameter. The prostrate species are mostly alpine plants growing at high altitudes (e.g. ''C. integrifolius'', which grows at in the Himalayas), while the larger species occur in scrub and woodland gaps at lower altitudes.

Description

The shoots are dimorphic, with long shoots ( long) producing structural branch growth, and short shoots ( long) bearing the flowers; this pattern often developing a 'herringbone' form of branching. The leaves are arranged alternately, long, ovate to lanceolate in shape, entire; both evergreen and deciduous species occur.

The flowers are produced in late spring through early summer, solitary or in corymbs of up to 100 together. The flower is either fully open or has its five petals half open diameter. They may be any shade from white through creamy white to light pink to dark pink to almost red, 10–20 stamens and up to five styles. The fruit is a small pome diameter, pink or bright red, orange or even maroon or black when mature, containing one to three (rarely up to five) seeds.Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan . Fruit on some species stays on until the following year.

Wildlife value

''Cotoneaster'' species are used as larval food plants by some Lepidoptera species including grey dagger, mottled umber, short-cloaked moth, winter moth, and hawthorn moth. The flowers attract bees and butterflies and the fruits are eaten by birds.

Although relatively few species are native there, in the UK and Ireland, ''Cotoneaster'' species are used, along with the related genus '' Pyracantha'', as a valuable source of nectar when often the bees have little other forage in the June gap. Bees adore ''Cotoneaster''. The red berries are also highly attractive to blackbirds and other thrushes.

Cultivation and uses

Cotoneasters are very popular garden shrubs, grown for their 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.

Cotoneaster are also popular in the cultivation of bonsai trees, thanks to their hardiness, ability to fruit and flower, and their small leaf size.

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'' Flinck & B.Hylmö – ascending cotoneaster
* ''Cotoneaster assadii'' Khat.
* '' Cotoneaster assamensis'' G.Klotz
* ''Cotoneaster astrophoros'' J.Fryer & E.C.Nelson – starry cotoneaster
* ''Cotoneaster ataensis'' J.Fryer & B.Hylmö
* '' Cotoneaster atlanticus'' G.Klotz
* '' Cotoneaster atropurpureus'' Flinck & B.Hylmö – purple-flowered cotoneaster
* '' Cotoneaster atrovirens'' J.Fryer & B.Hylmö
* ''Cotoneaster atuntzensis'' J.Fryer & B.Hylmö
* ''Cotoneaster auranticus'' J.Fryer & B.Hylmö
* '' Cotoneaster bacillaris'' Wall. ex Lindl. – open-fruited cotoneaster
* ''Cotoneaster baenitzii'' Pax
* ''Cotoneaster bakeri'' G.Klotz
* ''Cotoneaster balticus'' J.Fryer & B.Hylmö
* ''Cotoneaster bilokonii'' Grevtsova
* ''Cotoneaster bisramianus'' G.Klotz
* ''Cotoneaster bitahaiensis'' J.Fryer & B.Hylmö
* ''Cotoneaster blinii'' H.Lév.
* ''Cotoneaster bodinieri'' H.Lév.
* ''Cotoneaster boisianus'' G.Klotz – Bois's cotoneaster
* '' Cotoneaster borealichinensis'' (Hurus.) Hurus.
* ''Cotoneaster borealis'' Petz. & G.Kirchn.
* '' Cotoneaster brachypodus'' Pojark. ex Zakirov
* ''Cotoneaster bradyi'' E.C.Nelson J.Fryer – Brady's cotoneaster
* ''Cotoneaster brandisii'' G.Klotz
* '' Cotoneaster brevirameus'' Rehder & Wilson
* ''Cotoneaster brickelli