Slippery Jacks have a dark brown cap, shiny in dry weather and slimy in wet weather. They have a large ring around the stem that initially covers the spore tubes and later, as it dries, adheres to the stem. The stem is yellowish above the ring and off-white below it. The pore surface is tightly packed and yellow in colour. The flesh is light yellow and soft, and does not change colour when cut.
The Larch Bolete (Suillus grevillei) and the Darker Suillus clintonianus mushroom are both associated with larches. The cap of the Larch Bolete is a brownish yellow, whereas S. clintonianus is a strong reddish brown. The Weeping Bolete (Suillus granulatus) is found mostly in southern Finland, is associated with spruce trees, and has no ring around the stem.
Slippery Jacks grow at the roots of spruce trees and are quite common in heath forests. They can often be found at the grassy edge of a forest path, yard, or park.
Slippery Jacks grow from July to early October.
Slippery Jacks should be picked when young because they quickly become soft and maggot-ridden. It is best to immediately cut off the slimy, tough, leather-like cuticle with a knife so that the mushrooms in the basket don’t get too messy. Slippery Jacks are delicious mushrooms and can be prepared as they are in a frying pan. They can be frozen, dried, or marinated.