Parodia ritteriana (Lisal & Kolarik) A. S. Oliveira & R. Pontes comb. nov.

≡ Notocactus ritterianus Lisal & Kolarik (1986: 5)

The species grows on vulcanic rocks and it is classified as critically endangered (CR) in its native habitat (IUCN 2022). The populations found are small and disjunct in an area of about 14 km 2. The threats observed were human activities associated with agriculture (removal of soil cover and removal of stones from the field) and livestock (grazing).