Species complexes in Hericium (Russulales, Agaricomycota) and a new species - Hericium rajchenbergii - from southern South America

Species of the genus Hericium are generally recognized by macro morphology of their basidiomes, while they are very similar in the microscope. As a result, species boundaries are not always clear, and many collections are subsumed under incorrect names. We report on a thorough phylogenetic analysis based on ITS sequences to clarify the application of the most common names in the genus. H. alpestre, H. americanum, and H. erinaceus cannot readily be distinguished by their ITS sequences alone, while they are kept separate by characters from substrate preferences, geographical distribution, and macro morphology. A neotype is selected for H. alpestre. A well supported clade includes H. coralloides together with other, unnamed taxa. One of these, H. rajchenbergii from Argentina, is here described as new to science.