This fungus is a Pluteus with distinctly free gills. It can reach 15 cm or more across, with a slender stipe and grows on hardwood, especially downed alder. It rarely is seen in deep forest but is fairly common in urban environments, where it grows on wood chips, stumps, etc. It smells and tastes of radish. Caps are smooth, white, and overlain with tiny blackish scales that radiate out from the somewhatg darker disc. Many Pluteus species have white morphs, such as the deer mushroom P. cervinus or P. exilis, with caps that in white morph form strongly resemble P. petasatus. However they also have stems with dark striation, not seen in P. petasatus. The gills start white, turn pinkish as the spores mature and then eventually salmon-colored. All Pluteus species grow on wood, but sometimes buried wood and all have free gills