Amanita nothofagi is a species of fungus in the Amanitaceae family. Endemic to New Zealand, the species was first described by mycologist Greta Stevenson in 1962. The fruit bodies have dark brown caps that are up to 13 cm (5.1 in) in diameter and covered with patches of soft greyish-brown scales or warts. The gills underneath the cap are crowded together, free from attachment to the stem, and white, becoming tinged with yellow in age. The stem of the mushroom is 4–14 cm (1.6–5.5 in) long by 0.5–2.5 cm (0.2–1.0 in) thick, and has a ring. The spore print is white, and individual spores are spherical to ellipsoid, measuring 7.5–9 by 7.5–9 micrometres. The mushroom may be confused with another New Zealand species, A. australis, but can be distinguished by certain characteristics. Amanita notho