Yaretalion

A yaretalion is an extremely rare tree that grows only in extreme cold climates. Its bark is white in winter and cream in summer. It has very special properties that help against the powers of some undead. This is what makes it one of the most sought-after plants by clerics fighting against these creatures.
The yaretalion bark decoction grants advantage on saving throws against energy drain, an ability possessed by creatures such as wights, specters, and wraiths, for a duration of 1 hour.