The magic of the rowan tree

The European rowan has a long tradition in
European mythology and folklore. It was thought to be a
magical tree and protection against malevolent beings. Often
it was planted near a farms to protect the farmer's family and
the farm animals. Rowan was carried on vessels to avoid storms,
kept in houses to guard against lightning, and even planted on
graves to keep the deceased from haunting. It was also
used to protect one from witches

Emile Claus (1849–1924): 'Cow'

File:Sif from Swedish Edda translation.jpg

Sif by Jenny Nyström, 1893

In Norse mythology the rowan was
associated with the goddess Sif and, particularly,
the god Thor as it was deemed his salvation as
the giantess, Gjalp, tried to drown him in
the rising flow of the Vimur River

File:Illustration Sorbus aucuparia0.jpg

Prof. Dr. Otto Wilhelm Thomé Flora von Deutschland,
Österreich und der Schweiz 1885

This is a photo by Anders Folkestadås of
Johannes Flote and Anton Reite castrating a
lamb, Folkestadbygd, Norway ca. 1900-1910.

In the comments it reads:

'Guttorm Flatabø raised the question of what the
object attached to Anton Reite's jacket is. I had a closer
look at the image, and think it might be a sprig of rowan.
Rowan was believed to have protective powers and considered
a holy tree in Norwegian (and European) folklore. Perhaps
that's why it's used in this situation?'

Fylkesarkivet i Sogn og Fjordane