The readily identifiable fruit bodies have caps that are dark red when fresh, dry to the touch, and covered with mats of hairs and scales that are separated by yellow cracks.

It has a disjunct distribution, and is found in eastern Asia, northeastern North America, and Mexico throughout the range of the host tree.

The first specimen was originally collected in New England in 1856 by Charles James Sprague, and a formal scientific description was published in 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.

[7] 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.

[5][nb 2] S. decipiens S. spraguei S. granulatus S. placidus S. americanus S. sibiricus S. subumbonatus S. intermedius S. subalutaceus S. cothurnatus, S. subluteus, S. subaureus A 1996 molecular analysis of 38 Suillus species used the sequences of their internal transcribed spacers to infer phylogenetic relationships and clarify the taxonomy of the genus.

[12] These results were corroborated and extended in later publications that assessed the relationships between Asian and eastern North American isolates of various Suillus, including S. spraguei.

The cap margin is initially rolled downward before straightening out, often with hanging remnants of partial veil (appendiculate).

[24] Michael Kuo's 2007 book 100 Edible Mushrooms rates the taste as mediocre, suggesting "its sluglike consistency has all the palatability of unflavored gelatin."

The book recommends frying the thinly sliced mushroom in butter or oil until it acquires a crispy texture.

[18] S. spraguei is a popular edible among novice mushroom hunters as it is readily identifiable due to both its appearance and its association with white pine.

[28] S. decipiens has a less intensely red cap when young, but the color of older specimens fade and can resemble S. spraguei.

Further, its pores are irregular in shape, measuring 0.5–1 mm in diameter at maturity, and stain a shade of hazel rather than reddish to brownish.

[30] The fungus has ecological host specificity, and in natural soils can only associate with white pine, a grouping of trees classified in subgenus Strobus of the genus Pinus.

[35] A Japanese field study found that S. spraguei was the dominant fungus in a 21-year-old stand of Korean pine, both in terms of ectomycorrhizae (measured as percentage of biomass present in soil samples) and by fruit body production (comprising over 90% of dry weight of total fruit bodies collected of all species).

[36] The results also suggested that S. spraguei prefers to produce fruit bodies in areas with low litter accumulation, a finding corroborated in a later publication.

[42] In North America, its range extends from eastern Canada (Nova Scotia)[20] south to the Carolinas, and west to Minnesota.