Studies in Coprinus IV — Coprinus section coprinus. Subdivision and revision of subsection Alachuani

Coprinus section Coprinus is defined and delimited to comprise four subsections: Atramentarii, Coprinus, Lanatuli and Alachuani. A key to the subsections is given as well as a key to the species of subsection Alachuani known from the Netherlands or to be expected in the Netherlands on account of records from neighbouring countries. Three new species, Coprinus epichloeus, Coprinus fluvialis and Coprinus sclerotiorum are described as well as a new variety of C. urticicola: var. salicicola. In addition the following species are fully described: C. argenteus, C. echinosporus, C. episcopalis, C. filamentifer, C. friesii, C. gonophyllus, C. goudensis, C. herinkii, C. kimurae, C. kubickae, C. luteocephalus, C. phaeosporus, C. phlyctidosporus, C. picaceus, C. piepenbroekii, C. pseudofriesii, C. rugosobisporus, C. spilosporus, C. stanglianus, C. strossmayeri, C. tigrinellus, C. urticicola, C. vermiculifer, C. xantholepis, and C. xenobius.