Ritterocactus langsdorfii (Lehm.) Doweld in Sukkulenty 3: 60. 2000 Ritterocactus langsdorfii (Lehm.) Doweld in Sukkulenty 3: 60. 2000is new combination for Cactus langsdorfii Lehm., Index Sem. (Hamburg): 17. 1826Taxon for this nameRitterocactus langsdorfii (Lehm.) Doweld