Catharanthus roseus (Madagascar Periwinkle) is a species of Catharanthus native and endemic to Madagascar. Synonyms include Vinca rosea (the basionym), Ammocallis rosea, and Lochnera rosea; other English names occasionally used include Cape Periwinkle, Rose Periwinkle, Rosy Periwinkle, and "Old-maid".
Habituated cells of Catharanthusroseus (Apocynaceae) selected from an auxin-dependent line accumulated alkaloid in higher amounts than did the non-habituated cells grown in their maintenance medium. Ajmalicine and serpentine contents could be enhanced in both cell lines by feeding the indole alkaloid precursor secologanin or low concentrations of IAA or NAA.

The species has long been cultivated for herbal medicine and as an ornamental plant. In traditional Chinese medicine, extracts from it have been used to treat numerous diseases, including diabetes, malaria, and Hodgkin's disease.