Tylopilus variobrunneus
Description
Tylopilus variobrunneus is a bolete fungus in the family Boletaceae native to the United States. Stem darkens from buff white netting on top to brown netting, to dark brown base. The dark brown cap may have an olive edge, & ages to pale chestnut. White pores age pinkish & stain brown-pink. Dull white cap flesh stains pinkish. Young specimens often (not always) have olive-green tints in the cap, particularly around the edge.
Edible and bitterness vary. Sometimes good, sometimes a ruiner of meals.
It was described as new to science in 1998.
Mushroom Identification
Ecology
Mycorrhizal with oaks; growing alone, scattered, or gregariously; summer and fall; probably widely distributed east of the Rocky Mountains.
Cap
5–12 cm; convex when young, becoming broadly convex or nearly flat in age; dry; bald at maturity; medium grayish brown, fading to tan.
Pore Surface
Creamy white, becoming pinkish brown; bruising promptly brown; pores circular to angular, 1–3 per mm; tubes to 10 mm deep.
Stem
3–10 cm long; 1–2 cm thick; more or less equal; brownish; reticulate with a fine, brown reticulum; basal mycelium white.
Flesh
White; staining slowly brownish when sliced.
Odor and Taste
Odor is not distinctive; tastes mild, not distinctive.
Chemical Reactions
Ammonia pinkish-orange on cap surface; negative on flesh. KOH dark red to dark gray on cap surface; yellowish to orangish on flesh. Iron salts grayish-green on cap surface; bluish on flesh.
Spore Print
Brownish pink to pinkish brown.
Microscopic Features
Spores 10–13 x 3.5–4.5 µm; subfusiform; smooth; hyaline to yellowish in KOH. Hymenial cystidia fusoid-ventricose; golden in KOH. Pileipellis a collapsing trichoderm; golden in KOH; terminal cells cylindric with rounded or fusiform-cystidioid apices, 2.5–5 µm wide.
Photo sources:
Photo 1 - Author: Bill (boletebill) (CC BY-SA 3.0)
Photo 2 - Author: Bill (boletebill) (CC BY-SA 3.0)
Photo 3 - Author: walt sturgeon (Mycowalt) (CC BY-SA 3.0)
