The hazel tree, Corylus avellana, native to Europe, reproduces well thanks to forgetful squirrels who don’t return to collect hazelnuts they have hidden in the earth far away from the tree.
Corylus comes from Greek koros, meaning hood or helmet, referring to the shape of the foliar structure protecting the nut. Avellana is named after the city of Avella, in the Italian Province of Avellino, where common hazels are plentiful.
Description and flowering period
It is a low-branching shrub reaching from 2 to 5 meters in height, occasionally more and living around 60 years old. Its roots have a symbiotic relation with fungi (mycorrhiza), amongst which truffles. The deciduous leaves are slightly pubescent and ovoid to cordate (heart-shaped) with pointed tips and serrated margins. Flowering takes place in the winter. The species is monoecious, which means that each individual carries both male as well as female flowers. Individual flowers are tiny and have no petals, the male ones are numerous and borne on yellow catkins; female flowers are few and hidden under the buds’ scales, the only flower part showing being the red, linear stigmata. Pollination is anemophilous (it is wind-pollinated). The ovoid fruit, commonly called hazelnut, is botanically speaking an achene (a dry fruit which does not open on its own and contains a single seed). It can be solitary or in groups of 2 to 4 nuts, which have an outer smooth woody shell (the pericarp) and a single edible seed. Fruits are covered in an involucre (ensemble of reduced foliar structures) of toothed, bell-shaped papery bracts.
It requires a free-draining – preferably basic soil – at altitudes of up to 1700 meters. It can be planted in full sun as well as shade, and is hardy to -20°C.
- Food & drink: The fruit is eaten raw, used in sweet making, pastry cooking as well as oil and liqueur production. It is rich in trace-elements (Calcium, Iron, Magnesium…) and in vitamins (A, B, C, E).
- Medicinal: It is used for its detoxifying, antipyretic, astringent, anti-haemorrhagic, slimming and uplifting properties (catkins, leaves, bark, fruits and twigs).
- Craftsmanship: The soft wood is used in basketwork, cooperage and marquetry work.
- Miscellaneous: It is used as firewood, leaves can be smoked like tobacco; oil used as cosmetics (soaps…), branches were stacked against sheep pens to protect from wolves and snakes; the leaves were traditionally infused in milk to protect from the evil eye (Catalonia); young supple branches were used to make dowsing rods (in Celtic cultures).
It is widely grown for its fruits throughout southern Europe. Turkey is the largest international producer. The species’ dissemination is facilitated by squirrels who sometimes forget about the nuts they had previously hidden away from the parent tree.
Translated by: François Saint-Hillier – MNHN