Remarks: Pluteus rimosoaffinis was described from Argentina (Singer 1956) and since then it has been recorded from Brazil by Pegler (1997) and Meijer (2006 as P. cf. rimosoaffinis), but both records are not accompanied by a complete description. Singer (1956) mentioned in the protologue some characteristics that were not observed in the Brazilian collections, such as the entirely white stipe, the grayish-pallid lamellar edges, non-globose basidiospores, and the presence of obpyriform pleuro- and cheilocystidia. Moreover, we also observed some weakly pigmented pleurocystidia in the Brazilian material.
Although Singer (1956, 1959) emphasized the obpyriform shape of the cystidia, he also illustrated clavate and narrowly utriform pleuro- and cheilocystidia like some of those found in the Brazilian collections examined in the present study, even characterizing the cheilocystidia as more versiform than the pleurocystidia. Despite the differences between the Brazilian and the Argentinean collections, we still accept P. rimosoaffinis with these variations and confirm its occurrence in Brazil. The re-examination of the Argentinean collections studied by Singer (1956, 1959) would be useful, but the holotype is not available for loan and the other collections (including the paratype) mentioned in Singer’s papers were not found in LIL.