Heliocybe is an agaric genus[1] closely allied to Neolentinus and the bracket fungus, Gloeophyllum, all of which cause brown rot of wood.[2] [3] Heliocybe sulcata, the type and sole species, is characterized by thumb-sized, tough, revivable, often dried, mushroom fruitbodies, with a tanned symmetric pileus that is radially cracked into a cartoon sun-like pattern of arranged scales and ridges, distant serrated lamellae, and a scaly central stipe. Microscopically it differs from Neolentinus by the absence of clamp connections. Like Neolentinus, it produces abundant, conspicuous pleurocystidia. Heliocybe sulcata typically fruits on decorticated, sun-dried and cracked wood, such as fence posts and rails, vineyard trellises in Europe, branches in slash areas, and semi-arid areas such on sagebrush or on naio branches in rain shadow areas of Hawaii, or in open pine forests.[4] [5] [6] [7] __TOC__
Heliocybe derives from the Greek helios (= the sun) and cybe (=head), and means "the sun-head". It was coined in reference to its sun-like pattern on its pileus together with its affinity to sun-baked habitats.
In older classifications, H. sulcatahttps://web.archive.org/web/20071010102253/http://www.minnesotamushrooms.org/news/2004-02/mush-science.htm was known as Lentinus sulcatus or Panus fulvidus. However, there is strong phylogenetic evidence for the segregation of a group of brown rot causing fungi at the level of order, including Neolentinus and Heliocybe and Gloeophyllum, from the Polyporales where Lentinus and Panus are classified.[2] [3] [8] [9] [10] Heliocybe has also been placed into synonymy with Neolentinus, but anatomically they differ by the absence versus the presence of clamp connections[1] and phylogenetically Heliocybe is distinct, being either a sister group to Neolentinus or to a Neolentinus-Gloeophyllum-clade, or allied to Gloeophyllum odoratum.[2] [3] [9] [10]