urbpan | 100 Species #91: Bicolored bolete

This bicolored bolete (Boletus bicolor/campestris complex) was growing beneath our shagbark hickory tree in the front yard.

"Bolete" is a non-specific term for mushrooms that produce spores through a spongy surface rather than the more familiar "gills." At one time all such mushrooms were in the genus Boletus, but as knowledge increased, these were split into dozens of other genera. Now just a few species of boletes are boletus. One dangerous misconception about these mushrooms is that none are poisonous--or that simple rules can distinguish poisonous ones from edible ones. The truth is that identification to species is the only way to be sure any mushroom is poisonous, and several species of bolete can make a person quite ill.

Bicolored boletes are a complex of several species of yellow and red mushrooms with flesh that bruises blue when damaged. You can see in the photograph that when I pulled some grass around the mushroom (to get a clearer shot of the mushroom) my hand brushed against the spore bearing surface which quickly turned blue. Boletus bicolor is supposed to bruise slowly, while B. campestris bruises quickly--but campestris has very small pores, and this mushroom has relatively large pores. This specimen was also heavily water-logged, which could probably affect both field markings. It will have exist in ambiguous realm of a "species complex" for now.