Corylus avellana, the common hazel, 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.
It is closely related to Datura, belonging to the same nightshade family, solanaceae. Brugmansia blooms dangle like great trumpets or bells while Datura blooms stand erect.