Chaga
Inonotus obliquus · Inonotus polypores (Inonotus)
Special mushroom – look, don’t pick Red List: Not threatenedAlso: Clinker polypore
Not a mushroom for cooking; the hard mass is used for tea. Health benefits are not proven, and kidney damage has been reported with regular use because of its high oxalate content – ask a doctor before taking it. Removing it injures the birch; in someone else’s forest only with permission.
Recognise it safely – what matters
- Black, cracked “charcoal” lump on the trunk
- Rusty brown to golden yellow inside
- Almost always on living birch
Features
- Cap
- No cap: what you see is a lumpy, black, deeply cracked growth (10–40 cm) that looks charred – not a fruit body but a sterile fungal mass.
- Underside
- No pores on the outside; the actual fruit body forms rarely, under the bark after the tree has died.
- Stem
- No stem, grows out of the trunk.
- Flesh
- Rusty brown to golden yellow inside, corky-hard.
- Smell
- Hardly any.
- Spore print
- White to brownish (from the rare fruit body).
Season
JFMAMJJASOND
Habitat
On the trunk of living birches, rarely on alder or beech; more common in the north and in uplands. The growth stays on the tree for many years and can be seen all year round.
Bříza
Never identify mushrooms by pictures or an app alone. When in doubt, ask a mushroom expert – and only pick what you know for sure.