Chaga or Tinder fungus
Chaga and Tinder fungus are similar species that can be mixed up while foraging. The main visible difference: cap surface: Chaga — cracked, dry, Tinder fungus — smooth. The mushrooms also differ in the following features: cap colour, cap shape.
Not sure? Identify by photoSide by side
| Characteristic | Chaga | Tinder fungus |
|---|---|---|
| Use | Chaga: Medicinal, Not eaten | Tinder fungus: Not eaten |
| Size | Chaga: Large (over 15 cm), Giant (>25 cm) | Tinder fungus: Giant (>25 cm) |
| Cap colour | Chaga: Black, Dark brown, Rusty | Tinder fungus: Grey, Brown |
| Cap shape | Chaga: Irregular | Tinder fungus: Convex |
| Cap surface | Chaga: Cracked, Dry | Tinder fungus: Smooth |
| Hymenophore | Chaga: Smooth, Pored | Tinder fungus: Pored |
| Substrate | Chaga: Living tree, On wood | Tinder fungus: On wood, Living tree, Dead wood |
| Partner trees | Chaga: Birch, Alder | Tinder fungus: Beech, Oak, Birch |
| Growth habit | Chaga: Solitary, In groups | Tinder fungus: Solitary, In clusters from one base |
Same in both: edibility class, season, taste, smell, flesh colour change, stem, nutrition type.
When and where they meet
Together: January–December
What they look like
Cap, Hymenophore, Stem, Flesh, Smell
Cap
Chaga
Chaga has no cap. What you see on the birch is a growth 10–30 cm across, occasionally up to 40 cm, or sometimes a narrow strip up to a metre long running along a crack in the trunk. It's irregular and knobbly, bursts out through the bark and sits firmly on the tree with a broad base.
The surface is black, matt, dry and very hard, broken by deep cracks into small facets, like charcoal or burnt wood. The black colour comes from the pigment melanin. Around the edges, where the growth pulls away from the bark, the rusty brown interior often shows through.
Tinder fungus
The fruiting body is 5-50 cm across (sometimes up to 70+), hoof-shaped to semi-hoof-shaped and attached sideways to its host, with no stem. The upper surface is hard and corky, with distinct concentric zones of annual growth, each marking a separate year of life. It's grey-brown, grey or olive-grey, dark grey to blackish in old ones, and old fruiting bodies often have a cracked crust.
Hymenophore
Chaga
The growth has no underside with pores or gills: it's a sterile mass of fungal threads and produces no spores.
The true fruiting body appears once the tree, or part of it, has died, often on the opposite side of the trunk. It spreads under the bark as a thin crust 0.5–1 m long, whitish at first and then brown, made of tubes. Eventually the bark splits open and exposes a brown layer of pores. It is rarely seen.
Tinder fungus
The underside is a tube layer with fine, pale grey-brown pores (3-4 pores/mm), grey-brown to brown in colour. The spore print is white to pale cream.
Stem
Chaga
There's no stem. The growth comes straight out of the trunk, usually at an old wound or broken branch, and is fused to the wood so firmly that only an axe will remove it.
Tinder fungus
No stem.
Flesh
Chaga
Inside, chaga is dense, corky and woody. The colour is rusty brown, turning yellowish orange towards the wood, often with pale streaks. This bright interior is what sets chaga apart from other black growths on birch. It doesn't change colour when broken.
Tinder fungus
The flesh is very tough, corky-fibrous, rusty brown and leathery, as hard as wood and useless in the kitchen. The smell is faint and neutral.
Smell
Chaga
Chaga has no distinctive smell, and descriptions of the species don't mention one. Identify it by appearance instead: a black, cracked surface and a rusty yellow interior on a living birch.
Tinder fungus
Faint and neutral, nothing distinctive.
Related comparisons
Sources · 15
- [1]Index Fungorum
- [2]GBIF
- [3]MushroomExpert.com, Michael Kuo
- [4]Wikipedia (English)
- [5]Вікіпедія (українська)
- [6]Википедия (русская)
- [7]Memorial Sloan Kettering Cancer Center, About Herbs: Chaga Mushroom (2023)
- [8]Kikuchi Y. et al. Chaga mushroom-induced oxalate nephropathy. Clinical Nephrology, 2014, 81(6): 440–444, Kikuchi Y. et al. (2014)
- [9]Lee S. et al. Development of End Stage Renal Disease after Long-Term Ingestion of Chaga Mushroom. Journal of Korean Medical Science, 2020, 35(19): e122, Lee S. et al. (2020)
- [10]Kwon O. et al. Chaga mushroom-induced oxalate nephropathy that clinically manifested as nephrotic syndrome. Medicine (Baltimore), 2022, 101(10): e28997, Kwon O. et al. (2022)
- [11]Thomas P.W., Elkhateeb W.A., Daba G.M. Chaga (Inonotus obliquus): a medical marvel but a conservation dilemma? Sydowia, 2020, 72: 123–130, Thomas P.W., Elkhateeb W.A., Daba G.M. (2020)
- [12]BioImages: Inonotus obliquus
- [13]Атлас грибів України, Зеров Д.К. (1979)
- [14]MycoBank Database
- [15]iNaturalist Ukraine