Boletus flavoniger, B. lychnipes, B. neoregius, and B. quercophilus are new
ly described from Quercus dominated forests of Costa Rica. Boletus firmus,
a misunderstood taxon from eastern North America, is reported for the first
time in Costa Rica. Boletus neoregius and B. quercophilus have been found
in a number of sites throughout the country while B. flavoniger, B. lychnip
es, and B. firmus appear restricted to unique localities. Their exact distr
ibution outside of Costa Rica is unknown, but they may be expected in other
oak-dominated forests in Central America and northern South America.