The group of species called Salix – willows in plain English – are widespread throughout the Northern hemisphere and hybridise readily. Due to this and the introduction of numerous “ornamental” varieties over the centuries, it’s very difficult to declare particular species non-native, even when they do not apparently appear in the Otherworld.
As with everywhere else that willows, osiers and sallows inhabit, the Blessed Isles specimens are associated with healing due to the painkilling properties of the salicylic acid in their bark sap. They are often associated with crafting and building due to their woods’ pliancy. Male and female flowers grow on separate trees and the descriptions of their spirit forms seems to indicate that they are probably the source of or model for the more benevolent fairies.
The only point of willow-related folklore within the Blessed Isles that stands out is the English tradition that willow trees will uproot and stalk strangers to their area. It was even quoted in a number of letters between Welsh, Scottish and English heads of state in the late Middle Ages as proof that the English did not belong – at least in their neighbours’ countries. This behaviour has not been mentioned in any of the Rangers or Wardens records.