Although the Madagascar periwinkle has a flower adapted to pollination by a long-tongued insect, such as a moth or butterfly, this species, unlike most in the Apocynaceae family, is also able to self pollinate. Self compatibility and a relatively high tolerance of disturbance have enabled this species to spread from cultivation and naturalise in many parts of the world. As a consequence, this species is sometimes considered to be an invasive weed, although it does not normally proliferate sufficiently to eliminate native vegetation (3). The seeds of the Madagascar periwinkle are reportedly distributed by ants (2).
Traditionally, the Madagascar periwinkle has been used to treat a variety of ailments in Madagascar and in other parts of the world where the plant has naturalised. Whilst researching the anti-diabetic properties of the plant in the 1950s, scientists discovered the presence of several highly toxic alkaloids in its tissues. These alkaloids are now used in the treatment of a number of different types of cancer, with one derived compound (vincristine) credited with raising the survival rate in childhood leukaemia from less than 10 percent in 1960 to over 90 percent today (2) (3).