146. º Physarum rubiginosum Fr. & Palmquist, Symb. gasteromyc., fasc. 3: 21 (1818)

Specimen examined. PERU. Cusco: Anta, Chinchaypujio, Parccotica, Chinchipuya, Km 8,650, 3608 m, 13º34′07”S, 72º14′27”W, 17 Apr 2016, leaves of Alnus acuminata, Lado 24423 (MA-Fungi 95762).

Notes. Physarum rubiginosum has orange scales in the peridium and capillitium (Fig. 4C) with angular, calcareous concretions. Similar to Ph. lateritium (Berk. & Ravenel) Morgan, differing by its capillitium with calcareous concretions with rounded borders.

Known from Europe and North America (Poulain et al. 2011), in the Neotropics, it has been recorded from the Windward Islands, Jamaica, and Mexico (Lado & Wrigley de Basanta 2008). It is the first record for South America, inhabiting the litter of Alnus acuminata trees.