The son of Matholwch and Branwen, Gwern, is named after one of these objects.
The son of Matholwch and Branwen, Gwern, is named after one of these objects. According to the Auraicept, the letters of the ogham alphabet were named after these objects. Connla's well is surrounded by these objects. When Lleu Llaw Gyffes is sitting atop one of these objects, Gwydion lures him down with a magical song and turns him back into a human. Gwydion turns these objects into (*) warriors in the poem Cad Goddeu, which tells of a battle named for these objects. Pliny the Elder describes a ritual in which Druids climbed these objects. By eating the products of one of these objects, the Salmon of Knowledge gained its wisdom. For 10 points, name these plants often considered sacred by the Celts.
The son of Matholwch and Branwen, Gwern, is named after one of these objects.
trees [accept alder trees or oak trees]