Lately I have learned from a Lezayre source that even the sprays of the keirn or mountain ash – the luckiest thing that grows – should never be brought into a room, though crosses made of its wood may advantageously be hung up.
This may explain a puzzling incident related in my book, A Manx Scrapbook, in which a keirn shoot was left planted in a house that was being vacated…to cause misfortune to the next-comers.
The following rare exceptions to the witch-repelling power of the keirn may be worth noting. In Finland, though sacred, it is one of the five trees not created by God, but by the principle of evil. In Italy witches have been seen eating its berries and riding through the air on its branches. In Friesland, also, they eat the berries at their gatherings on St. John’s Eve.
(source: A Second Manx Scrapbook by W Walter Gill (1932))