The mushroom flesh has a very strong bluing reaction when cut or damaged and forms mycorrhizal relationships, primarily with conifers.

The species was first described scientifically by American mycologist Harry D. Thiers in 1965, based on collections he made in Jackson State Forest, Mendocino County, California, in late October 1962.

[3] It was transferred to Caloboletus by Italian mycologist Alfredo Vizzini in 2014,[4] following recent molecular studies that outlined a new phylogenetic framework for the Boletaceae.

The cap color is variable, ranging from buff to olive-buff to olive-brown; it stains brown when bruised or injured.

The flesh is whitish to pale yellow, and will quickly turn blue when cut or exposed to air.

The angular pores number about 1–3 per millimeter, and the tubes comprising the hymenophore are 8–16 mm (3⁄8–5⁄8 in) long.

[9] Somewhat similar in appearance is Caloboletus calopus, which also has a red and yellow stipe, and a dry tan-colored cap.

[10] Boletus coniferarum is distinguished from C. rubripes by its stem reticulation and by the absence of red coloration.