Overview
The Weeping Bolete (Suillus granulatus), also known as the Granulated Bolete, is a widespread, attractive pore mushroom native to pine woodlands across the Northern Hemisphere. Instantly recognizable by its rich chestnut to golden-orange slimy cap and its unique habit of exuding milky white droplets from its yellow pores in humid weather, this mushroom is an essential ectomycorrhizal partner of two-needle pine trees.
Biology and Physical Characteristics
Suillus granulatus features a smooth, distinctly viscid to slimy cap that dries to a glossy sheen, colored tawny-orange, cinnamon-brown, or yellow-buff. The pore surface underneath is bright pale yellow, turning ochre with age, with tiny angular pores that lack a partial veil. The pale yellow cylindrical stem is densely sprinkled near the apex with fine, glandular granules and dots that initially weep droplets of white milky latex before turning dark reddish-brown.
Behavior and Ecology
An obligate mycorrhizal partner, the Weeping Bolete forms an extensive subterranean fungal sheath around the feeder roots of pines, especially Scots pine (Pinus sylvestris), white pine (Pinus strobus), and red pine. It fruits abundantly in late summer and autumn following soaking rains, often appearing in large fairy rings or scattered troops across sandy, needle-carpeted forest floors.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, Suillus granulatus is one of the most abundant boletes in northern temperate forests. Prized by mushroom foragers for its mild, mushroomy flavor, it is traditionally peeled to remove the sticky, laxative cap cuticle before culinary preparation in soups, stews, and sautés.
Interesting Factoid
The Weeping Bolete earns its poetic name from its pores: young mushrooms in humid morning air literally ‘weep’ cloudy, pearl-like droplets of milky fluid from their tiny yellow pore mouths, which dry into dark reddish granules on the stem.