Ramaria ochraceovirens – synonym of Ramaria abietina
Resupinatus cyphelliformis – synonym of Hohenbuehelia cyphelliformis
Resupinatus trichotis – synonym of Resupinatus applicatus
Reticularia lycoperdon – synonym of Enteridium lycoperdon
Rhodocollybia maculata – synonym of Collybia maculata
Rhodocybe truncata – synonym of Rhodocybe gemina
Rickenella setipes – synonym of Rickenella swartzii
Rigidoporus sanguinolentus – synonym of Physisporinus sanguinolentus
Rigidoporus vitreus – synonym of Physisporinus vitreus
Rozites caperata – synonym of Rozites caperatus
Russuala atrorubens – synonym of Russula olivaceoviolascens
Russula emetica f. longipes – synonym of Russula emetica
Russula flava – synonym of Russula claroflava
Russula laccata – synonym of Russula olivaceoviolascens
Russula rosacea – synonym of Russula rosea
Russula sardonia – synonym of Russula drimeia
Rutstroemia firma – synonym of Poculum firmum