 The central portion of the cap becomes depressed in mature specimens.The cap surface is "verrucose"—covered with small angular or pyramidal erect warts (1–2 mm tall by 1–2 mm wide at the base); the warts are smaller and more numerous near the margin of the cap, and small fragments of tissue may be hanging from the margin of the cap.The cap surface, the warts, and the flesh are white.