The Common Hazel (Corylus avellana) is a species of hazel native to Europe and western Asia, from the British Isles south to Iberia, Greece, Turkey and Cyprus, north to central Scandinavia, and east to the central Ural Mountains, the Caucasus, and northwestern Iran. The scientific name avellana derives from the town of Avella in Italy, and was selected by Linnaeus from Leonhart Fuchs's De historia stirpium commentarii insignes (1542), where the species was described as "Avellana nux sylvestris" ("wild nut of Avella"). Common hazel is typically a shrub reaching 3-8 m tall, but can reach 15 m. The leaves are deciduous, rounded, 6-12 cm long and across, softly hairy on both surfaces, and with a double-serrate margin. The flowers are produced very early in spring, before the leaves, and are monoecious with single-sex wind-pollinated catkins. Hazelnuts are rich in protein and unsaturated fat. Moreover, they contain significant amounts of thiamine and vitamin B6, as well as smaller amounts of other B vitamins. Hazelnuts are extensively used in confectionery to make praline and also used in combination with chocolate for chocolate truffles and products such as Nutella. In the United States, hazelnut production is concentrated in two states, Oregon and Washington in the Pacific Northwest, with Oregon responsible for 99% of domestic production. In as of 1996[update] the in-shell production in Oregon was about 19,900 tons (18,000 tonnes) compared to 100 tons (91 tonnes) in Washington.