Slippery Jack: Suillus luteus


Suillus luteus is the type species of the genus Suillus. It is a most widespread summer and autumn fungus.  S. luteus is a common fungus indigenous to coniferous forests of Europe, Asia and North America, and introduced to New Zealand and southern Australia.

The common name Slippery Jack is an obvious reference to the slimy nature of caps of this mushroom during wet weather, although they are not particularly sticky during warm dry spells when they tend to be become smooth.

Suillus luteus is an edible mushroom although some authors regard it as one of low quality.The species is considered a delicacy in Slavic cultures. Some people may have allergic reactions or digestive problems, so some authors recommend discarding the glutinous cuticle and tubes before cooking.


Suillus luteus is a basidiomycete fungus mycorrhizal with various conifers mostly with species of genus Pinus, often on sandy or acid soil. It is usually found in groups in forests of Pinus recurring from summer to late autumn.

Fruit bodies of S. luteus have partial veil.  With the growth of fungi veil is disrupting and leaves distinct ring on the stipe surface. Ring is thin and broad, membranous, pale violet to brownish, often soon falling off. Stem is stout, cylindrical, with pale but soon darker brown glandural dots, can grow to 100 x 30 mm. Cap 50-110 mm, convex, viscid, fibrillose and shiny when dry, purplish chestnut to yellowish brown. Flesh white to lemon yellow in cap and vinaceous in stem base.

Sometimes it can be confused with Suillus collinitus due to the similarly colored fruit bodies but S. collinitus has no ring. Perhaps it can be replaced with Suillus granulatus because of the same habitat but it does not have neither partial veil nor ring.


In Croatia collecting, trade and management of fungi are regulated with „Pravilnik o zaštiti gljiva (Regulation on Fungi Protection)“ NN 34/2002. Suillus luteus is not a commercial type of fungi and cannot be collected for the purpose of processing, trade and other traffic, but only for personal consumption.


Croatian local name – Osinac




Dino Buršić M.Sc.; Croatian Forest Research Institute;