Oligoporus obductus (Berk.) Gilbertson & Ryv. syn. Osteina obducta (Berk.) Donk. Bone Polypore. Fruit body from one to several circular or spoon-shaped caps; up to 12 x 13 x 2cm; convex at first, then slightly depressed; white to grayish or buff; smooth. Tubes 1-3mm deep, slightly decurrent. Pores 3-5mm, minute, angular; white to yellowish. Stem 10-30 x 3-l0mm usually off-center (stems may also fuse together as in the example shown); white to cream. Flesh 3-l0mm thick; white. Spores cylindrical, smooth, 4.5-6.5 x 2-3µ. Deposit white. Habitat on dead conifers and birch. Found from northeastern North America across to the Pacific Northwest, California, and Colorado. Season July-November. Not edible. Comment The generic name Osteina means "bonelike" and refers to the extreme hardness of the dried fruit bodies.