Brewer's: Mountain Ash
(The), or “Rowantree,” botanically called Pyrus aucuparia, which does not belong to the same family of plants as the fraxinus, or Common Ash. The Mountain Ash is icosandria, but the Common Ash is diandria. The Mountain Ash is pentagunia, but the Common Ash is monogynia. The Mountain Ash is of the Natural Order rosaceæ, but the common Ash is of the Natural Order sepiariae; yet the two trees resemble each other in many respects. The Rowan or Rown-tree is called in Westmoreland the “Wiggentree.” It was greatly venerated by the Druids, and was called the “Witchen” by the early Britons, because it was supposed to ward off witches.
Their spells were vain. The hags returned To their queen in sorrowful mood, Crying that witches have no power Where thrives the Rowan-tree wood.
Laidley Worm of Spindleston Heughs (a ballad)