Discocactus placentiformis ((Lehmann) K. Schumann 1894) Etymology: From the Latin placenta (flat disc) and -formis (shaped like), in reference to its very flattened shape.Place of Origin: Brazil, specifically Minas Gerais, Bahia, and Goiás.
Discocactus zehntneri (Britton & Rose 1922) Etymology: In honor of Leo Zehntner, a biologist specialized in South American plants.Place of Origin: Brazil, state of Bahia.