Suillus caerulescens, commonly known as the douglas-fir suillus and fat jack, is a species of bolete fungus in the family Suillaceae.
The species was first described scientifically by American mycologists Alexander H. Smith and Harry D. Thiers in 1964.
The cap is yellowish to reddish brown, sometimes with streaks from its darker center. It ranges from in diameter, shaped convex to flat, and viscid when wet, sometimes with veil remnants on the edge. The flesh is yellowish, as are the pores. The stalk is yellowish to brown, darkening with age, 2âÂÂ8 cm tall, 1âÂÂ3 cm wide, and bruises bluish to brownish (often slowly), especially at the base. A faint ring may be present.
The flesh can have a lemony flavour. The spore print is reddish-brown.
Suillus lakei is fairly similar, as is S. ponderosus.
It can be found growing with Douglas-fir trees in western North America from October to December.
While edible, it is considered of mediocre to poor quality.