1 Star2 Stars3 Stars4 Stars5 Stars (27 votes, average: 3.89 out of 5)

Slippery Jack

Edible Edible
Autumn Autumn
Summer Summer

This slimy topped mushroom is common to Pine plantations and can usually be found close to paths in late Summer and Autumn. One of the few Bolete species to have a skirt.

Mushroom Type
Common Names Slippery Jack (EN), Boleg Llithrig (CY), Maślak Zwyczajny (PL), Barna Gyűrűstinóru (HU)
Scientific Name Boletus / Suillus luteus
Season Start Aug
Season End Sep
Average Mushroom height (CM) 5-9
Average Cap width (CM) 5-12
Please note that each and every mushroom you come across may vary in appearance to these photos.


5-12 cm long, 2-3 cm diameter. Dark brown to purple/brown with a very glutinous cap when wet, more rusty brown when dry. Starting convex and broadly flattening with age.


The pores are round, tightly packed and lemon yellow to dull yellow. When young they are covered by a veil which will break free from the cap forming the skirt.

Cortina / Veil

The veil completely covers the pores on young mushrooms.


5-9cm. Off white to yellow, more yellow above the skirt and covered in small brown granular spots.


Thick and white underneath, brown above from the dropping spores, on older mushrooms the underside can become pale lavender coloured or the whole ring can become just a mark on the stem.


White, sometimes with a red/purple flush towards the base. Unchanging when exposed to air.


With Pine, especially in Pine plantations.

Possible Confusion

The Larch Bolete (Suillus grevillei) can look similar but is more orange/yellow. A Larch Bolete variant (Suillus grevillei var. badius) is darker capped but also has a darker stem not the off white stem of Slippery Jack.

Spore Print

Brown. Subfusiform. The image is of the upper surface of the skirt where it has caught some dropping spores.


Common with pine.

Other Facts

It has been reported that the slimy skin on the cap can cause adverse reactions in some people so is best removed before cooking.


3 comments for Slippery Jack

  1. Pete says:

    Its about the slime that covers the cap, its hard to digest and some people can have gastric issues. Thats why its advised to remove the skin. You may also scratch some of the slime with knife ( need to scratch them off grass and dirt anyway) and soak mushrooms for few hours in very salty water to dissolve rest of it. Then a few good washes. Some people simmer them for few minutes as last stage. This way you can keep the skin, so they look better in a dish, but most importantly you dont have to sit and peel them one by one. Which due to slippery nature of this mushroom is quite annoying job.
    They make great sauce when cooked with butter and some onions.

  2. CBGastley says:

    I woke up this morning with my yard overgrown with these yellow slippery mushrooms. I picked 5 shovels full not knowing how f the would harm my dogs.

  3. Rick Graham says:

    The skin comes off these really easily: hold the mushroom with stalk towards you then break the cap gently in two away from you. You’ll find that the skin doesn’t quite break, so then you can easily peel the broken cap away from the skin.

Post a Comment

Your email address will not be published. Required fields are marked *