Super Mushrooms Reishi/Shiitake Blend A Dietary Supplement Vegetarian - Vegan Botanicals/Herbs Family Owned Since 1968 GMP Quality Assured NOW Rei-Shi Mushrooms is a blend of Reishi (also known as Ling Zhi) and Shiitake Mushrooms. Reishi and Shiitake are both well known in Oriental herbalism and have been used to promote health and wellness for centuries. In more recent years, researchers have identified key bioactive polysaccharides that may contribute to the health supporting properties of these two super mushrooms.