Amanita silvicola

Amanita silvicola, also known as the woodland amanita or kauffman's forest amanita, is a species of Amanita found in coniferous woods the Pacific Northwest and California.

A. silvicola is a small to medium-sized white mushroom, distinguishable from most other white Amanita species by its short stalk. Its cap ranges from 5–12 cm and is pure white, convex to flat, often with an incurved margin. The cap is initially rounded, covered in a "wooly" outer veil that later leaves soft patchy remnants across its surface as it flattens. The stem is patched with volva remains, and is slightly larger at its base. Gills are white, close and crowded, and free, just reaching the stem, or to narrowly adnate. The flesh of A. silvicola does not change colour when bruised or cut, but it's cap may discolour with age.

The edibibility of A. Silivicola is uncertain, but, due to its close resemblance to two poisonous mushrooms in the Amanita genus, A. pantherina and A. Smithiana, experimentation with this mushroom is strongly advised against.

Description
The cap of A. silvicola are 5 to 12 cm wide, dry and pure white in color. In advanced age and with decay, the cap may discolour, developing, as observed by Kauffman, "bright rose-colored spots and streaks". Younger fruiting bodies (mushrooms) are covered by a fluffy continuous universal veil, which breaks up irregularly across its slightly sticky surface into soft powdery patches instead of firm warts. The flesh of the cap thins considerably at its margin, which remains incurved into maturity. The gills are white and crowded together and have a free to narrowly adnate attachment, though sometimes reach towards the stipe in a deccurent tooth. The gills are medium broad, 6-7mm, with cottony edges, and in maturity they project below the margin of the cap. A. silvicola spores 8.0-10.0 μm by 4.2-6.0 μm, they are smooth, amyloid, ellipsoid and colourless, leaving a white spore print.

The stem is 50 to 120mm long,12 to 25mm thick and stout, tapering slightly as it reaches the cap. It sometimes has a slight ring on its cap. A. silvicola rarely roots, it has a basal marginate bulb (distinctly separate from the stem) at its base, about 3–4 cm thick with wooly veil remnants on its margin. The flesh of A. silvicola is white and does not change color when cut.

Habitat and distribution
Amanita silvicola is found in the Pacific northwest of North America, California, and more rarely in the Sierra Nevada mountains. The IUCN Red List has assessed it as Least Concern (LC), as the population is stable and "locally common" in the Pacific northwest and California. A. silvicola is a terrestrial species, it can be found as a solitary mushroom or in small groups in coniferous woods, especially under Western Hemlock. It has a preference for areas of high rainfall.

Taxonomy and Etymology
The species was first described and named by Kauffman in 1925, who had collected the type specimen in Mt. Hood, Oregon on September 30, 1922. The species epithet silvicola is derived from silva, Latin for "wood" or "forest", and -cola, Latin suffix for "dweller of" or "inhabiting", referring to its habitat.