The general term "Shimeji" refers to about 20 species of mushrooms which contributes to a great deal of confusion among both mycologists (mushroom scientists) and chefs. The hon-shimeji is referred to as the true shimeji and is highly esteemed in Japan where cultivation techniques were first developed. In nature, hon-shimeji grows on wood, often on beech trees hence the common name Beech Mushroom.
A recent unpublished report from the National Cancer Institute of Japan indicates that hon-shimeji mushrooms contains medicinally active ingrediants with strong anti-tumor activity. Additional studies are currently being conducted.