text: lactifluus piperatus lactifluus piperatus ( synonym lactarius piperatus ) , commonly known as the peppery milk - cap , is a semi - edible basidiomycete fungus of the genus lactifluus . despite being edible , it is not recommended because of its poor taste , though can be used as seasoning when dried . the fruiting body is a creamy - white mushroom which is funnel - shaped when mature , with exceptionally crowded gills . it bleeds a whitish peppery - tasting milk when cut . widely distributed across europe and eastern north america , lactifluus piperatus has been accidentally introduced to australia . mycorrhizal , it forms a symbiotic relationship with various species of deciduous tree , including beech , and hazel , and fruiting bodies are found on the forest floor in deciduous woodland . systematics and taxonomy the species was one of the many species named by linnaeus who officially described it in volume two of his species plantarum in 1753 as agaricus piperatus , the specific epithet deriving from the latin adjective piperatus meaning " peppery " . for many years , tyrolian naturalist giovanni antonio scopoli had been considered the author of the first description ; however , a recent revision of the international code of botanical nomenclature in 1987 changed the rules regarding the starting date and primary work for names of fungi . previously , the starting date had been set as january 1 , 1821 , the date of the works of the ' father of mycology ' , swedish naturalist elias magnus fries , but now names can be considered valid as far back as may 1 , 1753 , the date of publication of linnaeus ' seminal work . lactifluus piperatus was the original type species of the genus lactarius . however , after the finding that lactarius actually represented more than one genus , the species lactarius torminosus was conserved as type for that genus . thus , l. piperatus is now the type species of lactifluus , which was split from lactarius and contains mainly tropical milk - caps , but also some species of the north temperate zone . phylogenetic research showed that l. glaucescens , sometimes considered only a variety of l. piperatus , is a distinct species in europe . furthermore , the existence of at least ten lineages worldwide , with no overlap among continents , was shown for the group around l. piperatus , suggesting that populations in north america might actually be distinct species . it is commonly known as the peppery milk cap , pepper milkcap , peppery lactarius , peppery milk mushroom , white peppery milk - cap , or other similar names . similarly , in german it is known as the ( " pepper milk cap " ) . description lactifluus piperatus has a cap that varies from 6 – 16 cm ( 2 . 5 – 6 . 5 in ) across and is convex with a widely funnel - shaped center . the cap is creamy - white in colour , glabrous and not glossy ; its surface may become cracked in dry locales . the stipe is white in colour , smooth , 3 – 7 cm ( 1 – 3 in ) long by 2 – 3 cm ( 1 – 1 in ) thick and is cylindrical , sometimes tapering towards the base . there is a thick layer of firm white flesh , and the decurrent gills are particularly crowded and narrow , sharing the white colouration of the stem but becoming creamy with age . as with other species of lactarius , there is abundant milk ( latex ) , which is white , and dries olive - green . it has a white spore print with elongate , elliptic or amyloid spores which are ornamented , as with l. vellereus . the spores measure from 6 . 5 – 9 . 5 by 5 – 8 μm , and have tiny warts . l. vellereus is larger with a thick stipe , woolly cap and less crowded gills , but is not as tall . russula delica is similar in colour and shape , though has adnate blue - green tinged gills and no milk . l. deceptivus is also similar , but is differentiated by its less crowded gills , firmer cap margin and less acrid milk . close to l. piperatus is l. glaucescens , which is differentiated by its milk that dries with a greenish colour . distribution and habitat lactifluus piperatus in the wide sense , i.e. including probably several species , is found in europe , the black sea region in northeastern turkey , and eastern and central north america east of minnesota . it has been accidentally introduced into australasia , where it is found under introduced and native trees . it is found on the floor in deciduous woodland , particularly under beech ( betula ) , and can be found throughout summer and autumn and into early winter . it is relatively common , though not as common as the similar species l. vellereus . l. piperatus is found solitarily or in scattered groups . it is sometimes found growing together with russula . edibility despite being described by some mycologists as inedible or even poisonous , lactifluus piperatus is generally considered edible . however , it is not recommended , because of its unpleasant taste . it is difficult to digest when eaten raw , but is used as a seasoning when dried , or sometimes is eaten fresh after parboiling , though its taste is still . some recommend frying in butter with bacon and onion or pickling , or baking in a pie or pastry as other ways to prepare it . the milk has a very hot and acrid taste , which is removed if boiled . the mushroom used to be highly regarded in russia , where it would be picked in dry seasons when other edible species were less available . the mushroom is also popular in finland , where cooks boil it repeatedly , disposing of the water each time , and then store it in salt water and keep it refrigerated , after which it is pickled or served in salads . when eaten fresh and raw , the mushroom has been known to cause an irritant reaction on the lips and tongue , which subsides after an hour . the close l. glaucescens has been reported to be poisonous , but it has been speculated that the " poisonings " were caused by the extremely strong , peppery taste , rather than by the presence of actual poisons . lactifluus piperatus forms part of an unusual and highly regarded dish in north america , being one of several species parasitized by the lobster mushroom hypomyces lactifluorum . once colonized by the parasite , an orange - red crust forms over the surface of the mushroom , and the taste becomes delicious as the parasite infiltrates its host 's tissues . it is also a common source of food among red squirrels . other uses because of the presence of auxins in lactifluus piperatus metabolites , it can be applied as a rooting hormone to aid the growth of seedlings of various species of plants , including hazel , beech and oak . in the 19th century , it was used as a folk cure for tuberculosis , though it had no effect . in more recent times , it has been found that l. piperatus can be used as an antiviral agent , and the latex has been used against viral warts .