The Genus Gomphidius
[ Basidiomycota > Boletales > Gomphidiaceae . . . ]
by Michael Kuo
The mushrooms in Gomphidius are slimy-capped conifer lovers with dark gray to black spore prints, gills that run down the stem, and stems that are often--though not always--bright yellow near the base. The flesh in the cap and stem is white, and observation of this feature is sometimes the best way to separate species of Gomphidius from species of Chroogomphus, which can appear similar but feature orangish to yellowish or reddish flesh.
Although species of Gomphidius have gills rather than pores, they have evolved with the boletes in the Boletales, near the genus Suillus--which is perhaps not a big surprise, since species of Suillus are the slimy conifer lovers among boletes.
Identification of Gomphidius collections can often be accomplished without reference to microscopic features by paying careful attention to cap colors and, especially, whether or not a "slime veil" covers the young gills. The slime veil itself can be observed in button-stage specimens, but its presence can later be deduced, after the veil itself has broken, by the presence of slime on the stem. When microscopic examination is required for Gomphidius identification, it usually involves simple measuring of mature spores.