Although Caloboletus calopus is not typically considered edible due to an intensely bitter taste that does not disappear with cooking, there are reports of it being consumed in eastern Europe.

[6] Christiaan Hendrik Persoon described the mushroom in 1801;[7] its specific name is derived from the Greek καλος/kalos ("pretty") and πους/pous ("foot"), referring to its brightly coloured stipe.

[11] Boletus frustosus, originally published as a distinct species by Wally Snell and Esther Dick in 1941,[12] was later described as a variety of B. calopus by Orson K. Miller and Roy Watling in 1968.

[21] Sometimes, the reddish stipe colour of mature mushrooms or harvested specimens that are a few days old disappears completely, and is replaced with ochre-brown tones.

[22] Variety frustosus is morphologically similar to the main type, but its cap becomes areolate (marked out into small areas by cracks and crevices) in maturity.

[21] In the European form ereticulatus, the reticulations on the upper stipe are replaced with fine reddish granules, while the variety ruforubraporus has pinkish-red pores.

[25] Large pale specimens resemble Suillellus luridus, and the cap of Rubroboletus satanas is a similar colour but this species has red pores.

[25] Like C. calopus, the western North American species C. rubripes also has a bitter taste, similarly coloured cap, and yellowish pores that bruise blue, but it lacks reticulation on its reddish stipe.

[26] Found in northwestern North America, B. coniferarum lacks reddish or pinkish colouration in its yellow reticulate stipe, and has a darker, olive-grey to deep brown cap.

[22] The species grows on chalky ground from July to December, in Northern Europe,[24] and North America's Pacific Northwest and Michigan.

[21] In 1968, after comparing European and North American collections, Miller and Watling suggested that the typical form of C. calopus does not occur in the United States.

Similar comparisons by other authors have led them to the opposite conclusion,[32] and the species has since been included in several North American field guides.

[19][21][26] The bolete has been recorded from the Black Sea region in Turkey,[33] from under Populus ciliata and Abies pindrow in Rawalpindi and Nathia Gali in Pakistan,[34] Yunnan Province in China,[35] Korea,[36] and Taiwan.