[Old English hæsel; Old and Modern Irish Gaelic coll; Scottish Gaelic calltunn, calltuinn, Manx coull; Welsh collen; Cornish collwedhen; Breton kraoñk-levezenn] : Both the wood and the edible nuts of this bush or small tree (genus Corylus) have played an important roles in Irish and Welsh traditions. Hazel leaves and nuts are found in early British burial mounds and shaft-wells, especially at Ashill, Norfolk. The place-name story for Fordruim, an early name for Tara , describes it as a pleasant hazel wood (forest). In the ogham alphabet of early Ireland, the letter C was represented by hazel [OIr. coll]. It also represented the ninth month on the Old Irish calendar, 6 August to 2 September. Initiate members of the Fianna had to defend themselves armed only with a hazel stick and a shield; yet in the Fenian legends the hazel without leaves was thought evil, dripping poisonous milk, and the home of vultures. Thought a fairy tree in both Ireland and Wales, wood from the hazel was sacred to poets and was thus a taboo fuel on any hearth. Heralds carried hazel wands as badges of office. Witches' wands are often made of hazel, as are divining rods, used to find underground water. In Cornwall the hazel was used in the millpreve, the magical adder stones. In Wales a twig of hazel would be given to a rejected lover. Even more esteemed than the hazel's wood were its nuts, often described as the 'nuts of wisdom', e.g. esoteric or occult knowledge. Hazels of wisdom grew at the heads of the seven chief rivers of Ireland, and nine grew over both Connla's Well and the Well of Segais, the legendary common source of the Boyne and the Shannon. The nuts would fall into the water, causing bubbles of mystic inspiration to form, or were eaten by salmon. The number of spots on a salmon's back were thought to indicate the number of nuts it had consumed. The salmon of wisdom caught by Fionn mac Cumhaill had eaten hazel nuts. The name of the Irish hero "Mac Cuill" means 'son of the hazel'. W. B. Yeats thought the hazel was the common Irish form of the tree of life. source: Dictionary of Celtic Mythology by James MacKillop