text: russula brevipes russula brevipes is a species of mushroom commonly known as the short - stemmed russula or the stubby brittlegill . it is widespread in north america , and was reported from pakistan in 2006 . the fungus grows in a mycorrhizal association with trees from several genera , including fir , spruce , douglas - fir , and hemlock . fruit bodies are white and large , with convex to funnel - shaped caps measuring 7 – 30 cm ( 3 – 12 in ) wide set atop a thick stipe up to 8 cm ( 3 in ) long . the gills on the cap underside are closely spaced and sometimes have a faint bluish tint . spores are roughly spherical , and have a network - like surface dotted with warts . the mushrooms of russula brevipes often develop under masses of conifer needles or leaves of broadleaved trees , and fruit from summer to autumn . forms of the mushroom that develop a bluish band at the top of the stipe are sometimes referred to as variety acrior . although edible , russula brevipes mushrooms have a bland or bitter flavor . they become more palatable once parasitized by the ascomycete fungus hypomyces lactifluorum , a bright orange mold that covers the fruit body and transforms them into lobster mushrooms . taxonomy russula brevipes was initially described by american mycologist charles horton peck in 1890 , from specimens collected in quogue , new york . it is classified in the subsection , a grouping of similar russula species characterized by having whitish to pale yellow fruit bodies , compact and hard flesh , abundant lamellulae ( short gills ) , and the absence of clamp connections . other related russula species with a similar range of spore ornamentation heights include russula delica , r. , and r. . there has been considerable confusion in the literature over the naming of russula brevipes . some early 20th - century american mycologists referred to it as russula delica , although that fungus was described from europe by elias fries with a description not accurately matching the north american counterparts . fries 's concept of r. delica included : a white fruit body that did not change color ; a smooth , shiny cap ; and thin , widely spaced gills . to add to the confusion , rolf singer and later robert kühner and henri romagnesi described other species they named russula delica . robert shaffer summarized the taxonomic conundrum in 1964 : russula delica is a species that everybody knows , so to speak , but the evidence indicates that r. delica sensu fries ( 1838 ) is not r. delica sensu singer ( 1938 ) , which in turn is not r. delica sensu kühner and romagnesi ( 1953 ) … it is best to use r. brevipes for the north american collections which most authors but not kühner and romagnesi ( 1953 ) , call r. delica . the name , r. brevipes , is attached to a type collection , has a reasonably explicit original description , and provides a stable point about which a species concept can be formed . shaffer defined the russula brevipes varieties acrior and in 1964 from californian specimens . the former is characterized by a greenish - blue band that forms at the top of the stipe , while the latter variety has large spores . the nomenclatural database index fungorum does not consider these varieties to have independent taxonomical significance . in a 2012 publication , mycologist mike davis and colleagues suggest that western north american russula brevipes comprise a complex of at least four distinct species . according to mycobank , the european species russula is synonymous with r. brevipes , although index fungorum and other sources consider them distinct species . the specific epithet brevipes is derived from the latin words brevis " short " and pes " foot " , hence " short - footed " . common names used to refer to the mushroom include short - stemmed russula , short - stalked white russula , and stubby brittlegill . description fully grown , the cap can range from 7 to 30 cm ( 3 to 12 in ) in diameter , whitish to dull - yellow , and is funnel - shaped with a central depression . the gills are narrow and thin , decurrent in attachment , nearly white when young but becoming pale yellow to buff with age , and sometimes forked near the stipe . the stipe is 3 – 8 cm long and 2 . 5 – 4 cm thick . it is initially white but develops yellowish - brownish discolorations with age . the mushroom sometimes develops a pale green band at the top of the stipe . the spore print is white to light cream . spores of r. brevipes are egg - shaped to more or less spherical , and measure 7 . 5 – 10 by 6 . 5 – 8 . 5 µm ; they have a partially reticulate ( network - like ) surface dotted with warts measuring up to 1 µm high . the cap cuticle is arranged in the form of a cutis ( characterized by hyphae that run parallel to the cap surface ) comprising interwoven hyphae with rounded tips . there are no cystidia on the cap ( pileocystidia ) . the variant r. brevipes var. acrior shaffer has a subtle green shading at the stipe apex and on the gills . r. brevipes var. has spores measuring 9 – 14 by 8 – 12 µm . similar species the subalpine waxy cap ( hygrophorus subalpinus ) is somewhat similar in appearance to r. brevipes but lacks its brittle flesh , and it has a sticky , glutinous cap . the pacific northwest species russula also resembles r. brevipes , but has an acrid taste and smaller fruit bodies . another lookalike , r. , has gills that often fork near the stipe attachment . r. is quite similar to r. brevipes , but has narrower spores measuring 6 . 5 – 8 . 5 by 4 . 5 – 5 µm , and it does not have the pale greenish band that sometimes develops in the latter species . the european look - alike r. delica is widely distributed , although rarer in the northern regions of the continent . similar to r. brevipes in overall morphology , it has somewhat larger spores ( 9 – 12 by 7 – 8 . 5 µm ) with a surface ornamentation featuring prominent warts interconnected by a zebra - like patterns of ridges . the milk - cap mushroom lactifluus piperatus can be distinguished from r. brevipes by the production of latex when the mushroom tissue is cut or injured . distribution and habitat it is a common ectomycorrhizal fungus associated with several hosts across temperate forest ecosystems . typical hosts include trees in the genera abies , picea , pseudotsuga , and tsuga . the fungus has been reported in pakistan 's himalayan moist temperate forests associated with pinus . fruit bodies grow singly or in groups ; fruiting season occurs from summer to autumn . in western north america , where the mushroom is quite common , it is encountered most frequently in late autumn . the mushrooms are usually found as " " — low , partially emerged mounds on the forest floor , and have often been partially consumed by mammals such as rodents or deer . studies have demonstrated that geographically separated r. brevipes populations ( globally and continentally ) develop significant genetic differentiation , suggesting that gene flow between these populations is small . in contrast , there was little genetic differentiation observed between populations sampled from a smaller area ( less than approximately 1000 meters ) . r. brevipes is one of several russula species that associates with the myco - heterotrophic orchid abortivum . edibility russula brevipes is a non - descript edible species that tends to assume the flavors of meats and sauces it is cooked with . it is one of several russula species harvested in the wild from mexico 's - popo national park and sold in local markets in nearby . the mushrooms are suitable for pickling due to their crisp texture . fruit bodies are commonly parasitized by the ascomycete hypomyces lactifluorum , transforming them into an edible known as a lobster mushroom . in this form , the surface of the fruit body develops into a hard , thin crust dotted with minute pimples , and the gills are reduced to blunt ridges . the flesh of the mushroom — normally brittle and crumbly — becomes compacted and less breakable . bioactive compounds lactones are a diverse group of biologically active compounds that are being investigated for their antiinflammatory and antitumor activities . some of these compounds have been isolated and chemically characterized from russula brevipes : , lactarorufin - a , and 24 - ethyl - - - diene - 3β , 5α , - .