Bovine Jack

Suillus bovinus produces spore-bearing fruit bodies, often in large numbers, above ground. The mushroom has a convex grey-yellow or ochre cap reaching up to 10 cm (4 in) in diameter, which flattens with age. Like other boletes, it has tubes extending downward from the underside of the cap, rather than gills; spores escape at maturity through the tube openings, or pores. The pore surface is yellow. The stipe, more slender than those of other Suillus boletes, lacks a ring.

A common fungus native to Eurasia, it has been introduced to North America and Australia. The fungus grows in coniferous forests in its native range, and pine plantations in countries where it has become naturalised. It forms symbiotic ectomycorrhizal associations with living trees by enveloping the tree's underground roots with sheaths of fungal tissue, and is sometimes parasitised by the related mushroom Gomphidius roseus. Suillus bovinus is edible, but not highly regarded.