Family: Apocynaceae
Common Name: Madagascar Periwinkle

This is a genus of about eight evergreen annual or perennial plants mostly from Madagascar; only one species is commonly cultivated.

Species

C. roseus, Madagascar periwinkle, is a slightly succulent, evergreen perennial which grows 30-50 cm (12-20 in) high. Flattish flowers, typically in rose pink, red, white or mauve, are produced over many months, during spring and summer. There are several cultivars. All parts of the plant will cause severe burning and irritation if they are ingested. However, this plant also contains numerous alkaloids which have been used in the manufacture of drugs to treat leukaemia in children. These alkaloids can also cause reactions.

Cultivation

Grown as a seasonal annual in cool climates, this plant is often cultivated for massed display or for long-lasting potted colour. It needs well-drained soil, with some added humus, plenty of water during the warmer months and occasional applications of fertilizer. Water sparingly in winter and propagate from seed or cutting.

Climate

Zone 10, but grown as a summer annual in cool climates.