Sweet chestnut (Castanea sativa)
Flowering: June - July
The tree may reach up 25 to 35 meters height. The large lanceolate and toothed leaves are alternate. The trunk gradually becomes brownish-black over time and its thick bark is fissured in length. The male flowers grow in erect yellowish catkins, with female flowers at their base. The sweet chestnut fruits, called nuts, are enclosed by 1-3 in a spiny bur.
These species are adapted to full sunlight and high temperature but they are also intermediate shade tolerant. European chestnut is planted in undergrowth, along roads and parks.
Flowers pollination is mediated by the wind and insects. Its pollen is allergenic.
Cross-reactive allergy: there is cross-reactivity between the Fagaceae pollens (sweet chestnut, beech and oak) and the Betulaceae pollens (alder, birch, hornbeam and hazel).