Hazel (Corylus)

Family:

Birch family (Betulaceae)

Flowering period:

January to April

Distribution:

Distributed in the northern hemisphere in woods, hedges and gardens, medium sized shrub or tree, forest companions, occurs in the plains to upland areas, especially along forest edges

Appearance:

deciduous multi-stemmed shrubs or single-stemmed trees, deciduous leaves are simple, the leaf blade is broadly ovate, base often heart-shaped (cordate), double serrated leaf margin, lower leaf surface usually covered with fine hair, male inflorescences = catkins standing on the branches in grape-like groups, above the catkins are the bud-shaped female flowers with striking red style

Important species in Europe:

Corylus avellana (hazel): often present as the ornamental (Corylus avellana 'Contorta'), the well-known nut mainly originate from the “filbert” (Corylus maxima) that is widespread in south-eastern Europe and Asia Minor and more cold-sensitive than the common hazel.

Corylus colurna (Turkish hazel): native in southeastern Europe and Asia Minor, is also planted as ornamental in Europe.

Allergenicity:

moderate allergen potency and presence, frequent cross-reactions to hazelnut (food allergy) and the pollen of birch, alder and hornbeam; major allergen Cor a1

Link zum Pollenatlas: Corylus avellana