Grifola frondosa Fruiting Body Identity & Part
The botanical entity is Grifola frondosa (Dicks.) Gray, a polypore fungus of the family Grifolaceae that forms clustered, overlapping fronds at the base of trees. The part used is the fruiting body, the visible mushroom, and not the mycelium or the grain on which mycelium is grown. Stems and spent substrate are not added to this maitake mushroom extract.
Maitake is easy to confuse with the unrelated chicken-of-the-woods, Laetiporus sulphureus, and with Polyporus umbellatus, a different medicinal polypore once placed in the same genus. A specification that says only “maitake” or “mushroom” does not fix the species or the part. The fruiting body contains beta-glucan polysaccharides, proteins, ergosterol and minerals, of which the water extract concentrates the soluble polysaccharide part.












