''Lactifluus'' is one of three genera of

mushroom A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom. The standard for the n ...

-forming fungi containing species commonly named " milk-caps", the others being ''

Lactarius ''Lactarius'' is a genus of mushroom-producing, ectomycorrhizal fungi, containing several Edible mushroom, edible species. The species of the genus, common name, commonly known as milk-caps, are characterized by the milky fluid ("latex") they ex ...

'' and '' Multifurca''. It has been separated from ''

'' based on

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

evidence but is very similar to that genus. There are roughly 150 known ''Lactifluus'' species, which have a mainly

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

distribution but are also found in the north temperate zone and

Australasia Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different context ...

. Some of them are

edible mushroom Edible mushrooms are the fleshy fruit bodies of numerous species of macrofungi (fungi that bear fruiting structures large enough to be seen with the naked eye). Edibility may be defined by criteria including the absence of poisonous effect ...

Taxonomy

The genus ''Lactifluus'' was described in 1806 by French naturalist Henri François Anne de Roussel, with the type species ''

Lactifluus piperatus ''Lactifluus piperatus'' (synonym ''Lactarius piperatus''), commonly known as the blancaccio, is a basidiomycete fungus of the genus '' Lactifluus''. It was the original type species of the genus ''Lactarius'', before being moved to ''Lactifluus ...

''. Later, ''Lactifluus'' was largely considered a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of ''Lactarius'', until

work showed in 2008 that ''

'' was not a

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

group. In the following, the name ''Lactarius'' was conserved for the biggest of the sub

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

s revealed, containing most well-known north temperate species. Thus, the name ''Lactifluus'' could be used for the smaller genus, necessitating only a few name changes, as combinations with ''Lactifluus'' had already been made previously for many temperate species. New combinations have since been proposed for several species formerly classified in ''Lactarius''. A phylogenetics-based revision in 2017 divided the genus in four

subgenera In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ...

: ''Lactifluus'', ''Lactariopsis'', ''Gymnocarpi'' and ''Pseudogymnocarpi''. They are further subdivided into

section Section, Sectioning, or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sig ...

, but not all species are assigned to named sections. Many of these new groups do not correspond to previous subdivisions based mainly on morphology.

Selected species

Lactifluus_sp_G3264_pleurotoid_French_Guiana_cropped

, there are roughly 150 described species, classified in four subgenera. Some notable species are listed below under their respective subgenera. * Subgenus ''Lactifluus'' :* '' Lactifluus corrugis'' – 'corrugated-cap milky' (North America) :* ''

'' – 'peppery milk-cap' (Europe and North America) :* '' Lactifluus volemus'' – 'weeping milk-cap' or 'voluminous-latex milky' (North and Central America, Europe, Asia) * Subgenus ''Lactariopsis'' :* '' Lactifluus aureifolius'' (tropical Africa) :* '' Lactifluus deceptivus'' – 'deceiving milk-cap' (North and Central America) :* '' Lactifluus densifolius'' (tropical Africa) :* '' Lactifluus edulis'' (tropical Africa) :* '' Lactifluus heimii'' (tropical Africa) :* ''

Lactifluus vellereus ''Lactifluus vellereus'' (formerly ''Lactarius vellereus''), commonly known as the fleecy milk-cap, is a quite large fungus in the genus ''Lactifluus''. It is one of the two most common milk-caps found with beech, beech trees, with the other bei ...

'' – 'fleecy milk-cap' (Europe) * Subgenus ''Gymnocarpi'' :* '' Lactifluus clarkeae'' (Australia and New Zealand) * Subgenus ''Pseudogymnocarpi'' :* '' Lactifluus hygrophoroides'' (North America)

Description

''Lactifluus'' closely resembles its lookalike genus ''Lactarius'', with whom it shares the brittle flesh of the fruit bodies and the milk-like latex exuded when bruised. So far, synapomorphic characters for the genus have not been discovered, there are only tendencies that distinguish it from ''Lactarius''. Pleurotoid (laterally stiped) fruitbodies are only known in ''Lactifluus'', while species with closed (angiocarpous) fruitbodies only occur in ''Lactarius''. Microscopically, thick-walled elements in the

pileipellis The pileipellis is the uppermost layer of hyphae in the pileus of a fungal fruit body. It covers the trama, the fleshy tissue of the fruit body. The pileipellis is more or less synonymous with the cuticle, but the cuticle generally describes ...

and stipitipellis (

cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...

of the stipe) and sphaerocytes in the trama of the

lamellae Lamella (: 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 * Lame ...

are common in ''Lactifluus'', but rare in ''Lactarius'' species.

Edibility

Several species in the genus are edible. '' Lactifluus volemus'' especially is a choice mushroom in the northern temperate region.

References

External links

* {{Taxonbar, from=Q15991147 Russulales genera