- b rown ▁cap , ▁bright ▁yellow ▁cap ▁flesh , ▁and ▁a ▁stem ▁covered ▁by ▁fur fur ace ous ▁to ▁pun ct ate ▁orn ament ation ▁and ▁dark ▁red ▁hair s ▁at ▁the ▁base . ▁Its ▁flesh ▁instantly ▁st ains ▁blue ▁when ▁cut , ▁but ▁slowly ▁f ades ▁to ▁white . ▁The ▁fruit ▁bodies ▁are ▁poison ous , ▁and ▁produce ▁sympt oms ▁of ▁g astro int est inal ▁dist ress ▁if ▁consum ed . ▁ ▁Tax onomy ▁ ▁The ▁species ▁was ▁originally ▁described ▁by ▁American ▁my colog ist ▁Charles ▁H orton ▁Pe ck ▁in ▁ 1 8 8 9 ▁from ▁spec im ens ▁collected ▁in ▁Sar at oga , ▁New ▁York . ▁In ▁ 1 9 4 7 ▁R olf ▁S inger ▁described ▁form ▁gl ab ri pes ▁from ▁spec im ens ▁he ▁collected ▁in ▁A lach ua ▁County , ▁G aines ville , ▁Florida . ▁Syn onym s ▁include ▁names ▁resulting ▁from ▁generic ▁trans fers ▁to ▁the ▁gener a ▁Su ill us ▁by ▁Otto ▁K unt ze ▁in ▁ 1 8 8 8 , ▁and ▁to ▁Su ille lus ▁by ▁William ▁Al ph onso ▁M urr ill ▁in ▁ 1 9 4 8 . ▁ ▁The ▁m ush room ▁is ▁commonly ▁known ▁as ▁the ▁" red - mouth ▁bo lete ". ▁In ▁his ▁original ▁description , ▁Pe ck ▁called ▁it ▁the ▁" vel v ety - st em med ▁bo lete ". ▁ ▁Description ▁▁ ▁The ▁cap ▁is ▁initially ▁convex , ▁but ▁fl att ens ▁out ▁as ▁it ▁m atures , ▁att