The late Oligocene flora from the Nirmer Tunnel at the south-western edge of the Lower Rhine Basin was first described by Menzel (1913). A revision of Menzel’s original material indicates that most taxa are from the vegetation of riparian forests (Magnolia burseracea, Ocotea rhenana, Rhodoleia bifollicularis, Eotrigonobalanus furcinervis, Trigonobalanopsis rhamnoides, Sparganium sp. vel Typha sp.) and mesophytic forests (Carpolithes dactyliformis, Sapotacites minor). Some specimens cannot be identified, so they are named Dicotylophyllum div. spp. here. The fossil species Carpolithes dactyliformis (sandstone imprints and endocasts) belongs to Cornaceae subfamily Mastixioideae and is lectotypified here. The floral assemblage is compared with some similar floras from the Oligocene of Central Europe.