Biological Flora of the British Isles:<i>Crataegus monogyna</i>

This account presents information on all aspects of the biology Crataegus monogyna Jacq. (Hawthorn) that are relevant to understanding its ecological characteristics and behaviour. The main topics presented within standard framework Biological Flora British Isles: distribution, habitat, communities, responses biotic factors, environment, structure physiology, phenology, floral seed characters, herbivores disease, history conservation. is native flora, occurring frequently in hedgerows, scrubs, thickets woodland. It can be found throughout almost Europe, soils medium conditions regarding pH value, nutrient water supply. a deciduous shrub or rarely small tree 2–8 m. Its twigs branches bear sharp thorns about 1 cm long. both ornamental value. During flowering May June, shrubs may appear white through multitude flowers, presenting pollen nectar variety different insects. Starting August, whole become dark red with huge number berries (pomes) produced during fruiting. fruit preferred food for many birds. Although hybridizing freely other species, laevigata (Poir.) DC., two species easily recognizable natural stands Isles. Elsewhere, occurrence horticultural naturalizations intermediate forms hybrid origin closely related (especially similar looking one-styled rhipidophylla Gand. s.l. × subsphaerica s.l.) expert knowledge required avoid misidentifications thus inaccurate frequency distribution–not only continental Europe but also increasingly Identification field further complicated by inbreeding stock, which suffers from myriad descriptions given names at hierarchical levels. Cultivars commonly planted hedges along roadsides purposes. this stock not always known, so genetic exchange populations lead introgression genotypes more adapted than local changed environment.