Name in North American Boletes: Suillus intermedius AND Suillus subalutaceus
- Species 2: intermedius
- Species 3: subalutaceus
- Species 4: acidus var. intermedius
Common Name: “Sour Cap Suillus”
Tells: Cap ages from pinkish- or yellow-buff to yellow-brown. Cap skin usually tastes acidic. Oft-hollow buff- to tan-yellow stem has red-brown dots, & often a viscid, yellowish ring.
Other Information: Yellow to orange-yellow cap flesh may be pale or even whitish, esp. further away from the pores. Cap flesh DNS or slowly stains reddish brown. Buff-yellow pores age toward pale brown & slowly stain reddish brown. Likes pines, esp. in moss.
Science Notes: North American Boletes lists two mushrooms, “Suillus intermedius f/k/a acidus” and “Suillus subalutaceus”, distinguished by its lack of a sour taste. DNA testing has merged the two and moved the name back to “Suillus acidus” – which makes sense anyway because it hints at the key tell.
Edibility: Good, with a lemony flavor.
- NH4OH (Ammonia): Cap skin has no reaction. Cap flesh turns pink before shifting to grayish and then brown.
- KOH: Cap skin has no reaction. Cap flesh turns pink before shifting to grayish and then brown. Tubes turn wine-red to cinnamon.
- FeSO4 (Iron Salts): Cap skin has no reaction. Cap flesh turns greenish -blue, -gray, or- olive.