The fruit body is characterized by the reddish-pink (or pinkish-tan to yellowish if an older specimen) scales on the cap that are often found hanging from the edge.

Microscopically, B. ananas is distinguished by large spores with cross striae on the ridges and spirally encrusted hyphae in the marginal appendiculae and flesh of the stem.

The species was first named by Moses Ashley Curtis as Boletus ananas in 1848, based on specimens he found near the Santee River, in South Carolina.

[4] Wally Snell later doubted Murrill's conclusion in a 1933 publication; he considered the differences in the spore structure too great to consider the species conspecific with B. ananas, although he admitted it was impossible to come to any definitive conclusions until mature fruit bodies and spore prints were available for study.

The margin clasps the stem when young; at maturity it separates into triangular veil remnants (appendiculae) that measure 6–12 by 3–10 mm.

They are broadly and deeply depressed around the stem, of irregular lengths, bright yellow to olive-yellow to mustard-yellow, and also rapidly turn blue upon exposure.

The top part of the stem is cream to pink, the middle finely longitudinally striate, with the striations darkening with handling, red-lavender to brown-red, lighter with age.

The flesh of the stem is solid (i.e., not hollow) white to buff-tan to light yellow, and turns slightly blue with exposure.

They are abundant, arising from the subhymenium, projecting 19.3–29.6 μm above the hymenial palisade, thin-walled, hyaline, and devoid of refractive contents.

The cheilocystidia (cystidia on the edge of a gill) are 19–42 by 5–11 μm, swollen, cylindrical to narrowly cub-shaped, thin-walled, and infrequent.

The mediostratum (middle tissue layer) is 24.7–45.7 μm wide, and made of many parallel, slightly interwoven hyphae.

The lateral stratum hyphae are 4.4–8.4 μm wide, hyaline, gelatinized in a dilute solution of potassium hydroxide (KOH), and regularly septate.

The marginal appendiculae are composed of wefts of interwoven inflated hyphae, some with faint golden spirally arranged encrusting pigments that are evident when mounted in water, KOH, and Melzer's reagent.

The flesh of the stem is made of densely interwoven hyphae that are 4.9–7.2 μm wide, with spirally arranged, faint golden encrusting pigments that can be seen in KOH, Melzer's reagent, and water.

[19] The fruit bodies of B. ananas typically grow scattered or in groups under oak and pine trees, often on their bases.

[11] In Guyana, the mushroom typically fruits singly or in pairs within 1–2 m (3.3–6.6 ft) above ground level on the trunks of the tropical tree Dicymbe corymbosa (subfamily Caesalpinioideae), associated with ectomycorrhizas within humic accumulations.

[20] Harry D. Thiers, in his study of the bolete flora of Texas, wrote that B. ananas was a rare species that often fruited abundantly following an extended period of rain and high humidity.

[25] In Guyana, the humic deposits on Dicymbe trunks bearing B. ananas are consistently permeated with abundant ectomycorrhizas.