In "Teen Wolf" mountain ash also known as Sorbus_americana is a form of ash created from a tree that prevents supernatural creatures from crossing or touching. It was first introduced in Season 1. In real world mythology, it is often referred to as Rowan and supposedly has the ability to scare of evil beings. The mountain ash has also been said to keep supernatural creatures from causing trouble. The locked ward in Eichen House is filled with supernatural creatures, that part of the building is said to be made of mountain ash, it keeps the inmates from escaping.
Effects EditIts typically used by Druids to not only prevent creatures from getting past but according to Deaton modify their behavior as well. The ash seems to magically form a perfect circle or line when used, this has happened on multiple occasions, for example when Melissa McCall used it at her house to keep the Oni out her house, suggesting that the ash can be used by anyone with very little effort. Ms. Morrell created a perfect circle of mountain ash when protecting herself against the Alpha Pack. When used correctly, it can form a almost impenetrable barrier that no supernatural creature Lunar Ellipse" at the old distillery, potential True Alpha Scott McCall was able to force his way through it, he used all his force to break thought the barrier, this is something that was thought to be impossible. Another instance of a supernatural entity getting past the ash is when the Oni used their swords to find a weak spot and physically force their way through the mountain ash barrier. Other than those two instances, mountain ash ahs never been broken by a supernatural creature.
Mountain Ash has been shown to have no effect on chimeras due to their non-supernatural status. They can cross it, hold it, use it with absolutely no problem. In "Dreamcatchers, Tracy Stewart, a Werewolf-Kanima chimera was able to cross it as if it wasn't even there. Further proof on the ash having no powers over chimeras in when Werewolf-Werecoyote chimera, Theo Raeken was able to hold it and then use it against Scott McCall.
- Mountain ash has no effect on humans.
- Malia Tate referred to her first experience with mountain ash as weird.