Three new species of Lactarius (Russulaceae, Russulales) from Northeast China

Three new species of Lactarius are described from Northeast China, based on morphological comparisons and analyses on ITS nrDNA sequences. Samples of these species were mostly collected from deciduous or mixed forests with oaks. Lactarius albidocinereus, a member of L. subg. Plinthogalus is very similar to European L. azonites in the morphology and the sequence data. It differs from L. azonites by more ellipsoid spores with thinner ornamentation and shorter terminal cells in the pileipellis. Lactarius dilutisalmoneus belongs to L. sect. Zonarii of L. subg. Lactarius due to the pale salmoneus subzonate pileus with glabrous margin, unchanging latex and spore ornamentation composed of isolated elements. In comparison with its relatives, i.e. European L. zonarioides and North American L. olympianus, this new species has smaller spores with more prominent ornamentation. Lactarius olivaceorimosellus, a member of L. subg. Russularia, has areolate-rimulose pileus and lacks rosettes in the pileus and stipe cortex. Apart from the concentrically cracked pileus and absence of rosettes, the species can be easily distinguished by the olivaceo-brownish tinge of the pileus and spores with more dispersed elements of the ornamentation. Of the three species, at least L. albidocinereus represents a link with the Lactarius mycota of subtropical China.