 Suillus sibiricus is a fungus of the genus Suillus in the Suillaceae family . It is found in mountains of Europe , North America and Siberia , strictly associated with several species of pine tree . Due to its specific habitat and rarity in Europe , it has been selected for inclusion in several regional Red Lists . Its fruit bodies are characterised by having slimy caps in wet weather , which can reach diameters of up to 10 cm ( 3 @.@ 9 in ) . On the underside of the cap are yellow angular pores that bruise a pinkish to cinnamon colour . The stem is up to 8 cm ( 3 @.@ 1 in ) tall and 2 @.@ 5 cm ( 1 @.@ 0 in ) wide and typically has a ring , a remnant of the partial veil that covers the fruit body in its early development . In North America , it is commonly called the Siberian slippery jack . Phylogenetic analysis has shown that S. sibiricus is closely related to S. umbonatus and S. americanus , and may in fact be conspecific with the latter species . 
