Heliocybe is an

agaric An agaric () is a type of fungus fruiting body characterized by the presence of a pileus (cap) that is clearly differentiated from the stipe (stalk), with lamellae (gills) on the underside of the pileus. In the UK, agarics are called "mushroom ...

genus closely allied to ''

Neolentinus ''Neolentinus'' is a genus of wood-decaying agarics with tough (leathery to woody) fruit bodies composed of dimitic tissue, serrated lamella edges, and nonamyloid white binucleate basidiospores among other features. It was segregated from ''L ...

'' and the

bracket fungus A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. Typically deployed in symmetric pairs, an individual bracket may be identified as a 'left' or 'r ...

, ''

Gloeophyllum The genus ''Gloeophyllum'' is characterized by the production of leathery to corky tough, brown, shaggy-topped, revivable fruitbodies lacking a stipe and with a lamellate to daedaleoid or poroid fertile hymenial surfaces. The hyphal system is di ...

'', all of which cause brown rot of wood. ''Heliocybe sulcata'', the type and sole species, is characterized by thumb-sized, tough, revivable, often dried,

mushroom A mushroom or toadstool is the fleshy, spore-bearing fruiting body of a fungus, typically produced above ground, on soil, or on its food source. ''Toadstool'' generally denotes one poisonous to humans. The standard for the name "mushroom" is ...

fruitbodies, with a tanned symmetric pileus that is radially cracked into a cartoon sun-like pattern of arranged scales and ridges, distant serrated

lamella Lamella (plural lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal ...

e, and a scaly central stipe. Microscopically it differs from ''Neolentinus'' by the absence of

clamp connection A clamp connection is a hook-like structure formed by growing hyphal cells of certain fungi. It is a characteristic feature of Basidiomycetes fungi. It is created to ensure that each cell, or segment of hypha separated by septa (cross walls), rec ...

s. Like ''Neolentinus'', it produces abundant, conspicuous

pleurocystidia A cystidium (plural cystidia) is a relatively large cell found on the sporocarp of a basidiomycete (for example, on the surface of a mushroom gill), often between clusters of basidia. Since cystidia have highly varied and distinct shapes that ar ...

. ''Heliocybe sulcata'' typically fruits on decorticated, sun-dried and cracked wood, such as fence posts and rails,

vineyard A vineyard (; also ) is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice. The science, practice and study of vineyard production is known as viticulture. Vineya ...

trellises in Europe, branches in

slash Slash may refer to: * Slash (punctuation), the "/" character Arts and entertainment Fictional characters * Slash (Marvel Comics) * Slash (''Teenage Mutant Ninja Turtles'') Music * Harry Slash & The Slashtones, an American rock band * Nash ...

areas, and

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi- ...

areas such on

sagebrush Sagebrush is the common name of several woody and herbaceous species of plants in the genus '' Artemisia''. The best known sagebrush is the shrub '' Artemisia tridentata''. Sagebrushes are native to the North American west. Following is an al ...

or on naio branches in rain shadow areas of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...

, or in open

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

forests.

Etymology

''Heliocybe'' derives from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

'' 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.

Classification

In older classifications, ''H. sulcata

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 (biology), order, including ''Neolentinus'' and ''Heliocybe'' and ''Gloeophyllum'', from the

Polyporales The Polyporales are an order of about 1800 species of fungi in the division Basidiomycota. The order includes some (but not all) polypores as well as many corticioid fungi and a few agarics (mainly in the genus ''Lentinus''). Many species withi ...

where ''

Lentinus ''Lentinus'' is a genus of fungi in the family Polyporaceae. The genus is widely distributed, with many species found in subtropical regions. The genus name ''Lentinus'' is derived from the Latin ''lent'', meaning "pliable", and ''inus'', meani ...

'' and ''

Panus ''Panus'' is a genus of fungi in the family Polyporaceae. Species * (Senthil. & S.K.Singh) Senthil. (2015) *''Panus bacillisporus'' Kauffman (1930) *''Panus bartlettii'' Massee (1907) *''Panus biersianus'' Har. & Pat. (1914) *''Panus brunneipes' ...

'' are classified. ''Heliocybe'' has also been placed into synonymy with ''Neolentinus'', but anatomically they differ by the absence versus the presence of clamp connections and phylogenetically ''Heliocybe'' is distinct, being either a sister group to ''Neolentinus'' or to a ''Neolentinus-Gloeophyllum''-clade, or allied to ''Gloeophyllum odoratum''.

References

{{Taxonbar, from=Q4362787 Gloeophyllales Monotypic Basidiomycota genera