Of all wand types, alder is best suited to non-verbal spell work, whence comes its reputation for being suitable only for the most advanced witches and wizards.
-- Mr. Ollivander (Pm)
Alder is a type of wand wood (Pm).
- Ollivander states that alder is an "unyielding" wood, yet seeks a wizard who is "helpful, considerate, and most likeable" (Pm).
- Alder wands are the best for non-verbal spell work (Pm).
Old English alor "alder"
Alder bark contains "salicin" which is almost identical to aspirin, so the plant is used as a painkiller. Electric guitars and furniture are made from alder wood. source: Wikipedia