Tree branches tied into a whisk are one of the oldest tools of heat culture. In Russian banya this bundle is called a venik. It’s a way of working with warmth, air, and attention, and it carries the character of the tree it comes from.
The most common are birch and oak, each with its own logic. Birch feels lighter, brighter, more cleansing. Oak feels grounded, steady, and deep. Other trees appear too, depending on place and season: pine, eucalyptus, linden, juniper. Each type has its own texture and scent, and each asks for its own way of being used.