The taxonomic position of annual species of Oxalis section Alpinae, morphologically related to O. laxa, was controversial in recent publications of the genus. Several taxa have been treated as synonyms of O. laxa or, eventually, considered as accepted at the specific or infraspecific level. In this contribution, we evaluated the circumscription of O. micrantha and other names within O. laxa, while concluding that O. campanensis, O. cumingii, and O. rigida are clearly distinctive species based on morphological characters, different from the former; we also consider two varieties within O. laxa. Keys to distinguish the recognized taxa are presented, together with photos of the species. We also proposed lectotypes for the names O. dichotomiflora, O. laxa var. minor, O. platycaulis, O. puberula, O. sanromanii, and O. torcana.