(See Plate Facing Page 112)
Polyporus circinaius quite often has one cap within another. The caps are thick, round, without zones, velvety, and of a rusty-yellow colour. The lower surfaces of the caps, with the stems are woody and corky, but the upper surfaces of the caps are soft and woolly. The stem is swollen and covered with yellow wool. The pores are decurrent, minute, and unbroken, and of a dusky grey colour. This is a handsome species, especially remarkable for its double cap. The stem is an inch long and almost equally thick. The cap is three to four inches wide, and the flesh is uniform in colour.