Abstract

Cleome s.s. includes 22 species of herbs and shrubs with a center of distribution in southwest Asia and the Arabian Peninsula. The limits of Cleome s.s. and significant nomenclatural problems are addressed, with 21 lectotypifications (including two Linnaeus names), one significant syn. nov. designation, and treatment of 50 nomenclatural synonyms of the 22 species recognized. Two incertae sedis names are also discussed. A key to species and discussion of species complexes and particularly complicated nomenclatural problems are presented.