Ganoderma tsugae, also known as Hemlock varnish shelf, is a flat polypore mushroom of the genus Ganoderma. In contrast to Ganoderma lucidum, to which it is closely related and which it closely resembles, G. tsugae tends to grow on conifers, especially hemlocks. Like G. lucidum, G. tsugae is said to have medicinal properties. Phylogenetic analysis has begun to better differentiate between many closely related species of Ganoderma; however, there is still disagreement as to which have the most medicinal properties. In addition, variations within the same species as well as the growth substrate and environmental conditions all the way through to preparation can have a substantial effect on the medicinal value of the product.