Armillariella mellea Syn Agaricus sulphureus
(Vahl) P. Kummer
Armillaria mellea, commonly known as honey fungus, is a fungus in the genus Armillaria. It is a plant pathogen and part of a species complex of closely related and morphologically similar species. It causes root rot in many plant species and produces mushrooms around the base of trees it has infected. The symptoms of infection appear in the crowns of infected trees as discolored foliage, reduced growth, dieback of the branches and occasionally death. The fungus widely distributed in temperate regions of the Northern Hemisphere.
The cap is slimy when wet, and light to dark yellow, honey-colored, or brown, with fine hairs or scales over the center; gills are attached or running down the stem, white or cream (spotted brown with age); stem is white to buff or brown with the collar near top; black stringlike growths in nearby wood and soil.
The spores are white or pale cream.
Its preferred habitat is clusters on lawns, logs or stumps; sometimes at the base of trees.
The species was originally named Agaricus melleus by Danish-Norwegian botanist Martin Vahl in 1790; it was transferred to the genus Armillaria in 1871 by Paul Kummer. Numerous subtaxa have been described.