About Marasmius haematocephalus (Mont.) Fr.
Marasmius haematocephalus (Mont.) Fr. has a dark purple to blood red cap that measures 2.5–16 mm (0.098–0.630 in) in diameter. The cap is very thin, with deep striations running above the gills that give it a distinctive "pinwheel" appearance. Other species within this species complex may have caps of similar dark purple to blood red color, or they may have brown or pink caps instead. Its gills are free to narrowly adnate, distantly spaced, and range in color from white to cream. Like many species in the Marasmius genus, it produces a very thin, hard stipe. The stipe is mostly black, and lightens to match the gills' white to cream color at its apex. The stipe ranges from 22.4–62 mm (0.88–2.44 in) in height. Historically, this species was thought to have a pantropical distribution. Currently, it is accepted that Marasmius haematocephalus only occurs naturally in South America, and its type specimen was originally collected in Brazil. Members of its broader species complex have been collected in southeastern states of the USA, China, India, and South Africa.
