Suillus spraguei has had a complex taxonomic history. Although the first specimen was originally collected in New England in 1856 by Charles James Sprague, a formal scientific description was not published until 1872 when Miles Joseph Berkeley and Moses Ashley Curtis called it Boletus spraguei. In a publication that appeared the following year, American mycologist Charles Horton Peck named the species Boletus pictus. Berkeley and Curtis had also described what they believed to be a new species—Boletus murraii—although this was later considered by Rolf Singer to be merely a younger version of their Boletus spraguei.6 Although Peck’s description appeared in print in 1873, the date stamp on the original publication revealed that he had sent his documents to the printer before the appearance of the 1872 Berkeley and Curtis publication, thus establishing nomenclatural priority under the rules of fungal naming.7 However, in 1945 Singer reported that the name Boletus pictus was illegitimate because it was a homonym, already being used for a polypore mushroom described by Carl Friedrich Schultz in 1806.6[nb 1] The name was officially switched to Suillus spraguei in 1986 (Otto Kuntze had previously transferred the taxon to Suillus in 1898).
From Wikipedia — H.B