Hazels
What are they?
The hazels are a small group of deciduous trees and shrubs in the birch family (Betulaceae). Their male flowers form long, yellow catkins, often known locally as lamb's-tails and which are a much anticipated harbinger of spring - though they begin to form on the branches in the previous autumn. The female flowers are much smaller and consequently harder to spot. Thye appear at nodes a little further back along the twigs and consist of a cluster of red stigmas that protrude from a swollen base. After fertilisation, the bases swell further to become the well-known hazel nuts, which are typically half hidden by a cluster of leafy bracts. The Common Filbert (or hybrids of it and other species) is the species normally used to produce commercially grown filberts or hazelnuts, which are larger than those of our native species.
Where are they found?
Our native is common throughout the region in woods and copses as well as where planted in hedgerows and along roadsides. The introduced species may be found rarely in hedges or where planted in urban environments.
Identification
As a group, hazels are rather distinctive in their broadly rounded leaves and their male flowers which form showy catkins before the leaves appear in spring. Telling the shrubby species apart can be difficult (compounded by the fact that they hybridise!) and is best done by the appearance of the bracts that surround the fruits.
European Hazel Corylus avellana
Native. Widespread and common throughout the region. Formerly widely grown as a major component of coppice woodland to provide hazel rods for a variety of purposes. Also a common species in hedgerows. Flowers January to April. Forms a multistemmed shrub with long, cane-like stems. Leaves variable, rounded, but often with a 'shouldered' appearance resembling that of Wych Elm (but with a symetrical base). The leafy bracts surrounding the developing hazel nuts typically form a broad bell-shaped profile, widening towards the tips.
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Common Filbert Corylus maxima
Introduced from south-east Europe as a foodcrop and occasionally found where planted in hedgerows or amenity areas. Flowers January to April. Forms a multistemmed shrub with long, cane-like stems. Leaves variable but usually broadly rounded, to 14cm long and typically a little larger than those of European Hazel. The leafy bracts surrounding the developing hazel nuts typically enclose the fruits tightly, narrowing towards the tips. Amenity plants are often of purple-leaved forms.
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Turkish Hazel Corylus colurna
Introduced from Turkey as an ornamental. Seldom recorded but frequently planted as a street tree, especially in Norwich. Flowers January to April. Forms a single stemmed tree, typically forming a narrowly conical profile. Leaves with deeply toothed margins. The leafy bracts surrounding the large nuts are deeply cut and form large, bristly clusters that hang on pendulous stalks.
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