The vast island of Madagascar is the fourth largest in the world, possessing a unique 80% endemic biodiversity, while it remains one of the poorest of African nations. 
   The people traditionally practice subsistence agriculture using tavy, or slash-and-burn techniques, which means primary forest is quickly disappearing and secondary forest is degrading quickly with population growth and development. 
   The primary forest supplies many resources, not least of them is its rich pharmacopoeia.  Medicinal plants are an affordable alternative to Western medicine for Madagascar’s 15 million inhabitants (USAID 1999, the most recently available count).
   The famous Madagascar rosy periwinkle’s efficacy in treatments against childhood leukemia is proof of the potency and valuable resource that medicinal plants provide, especially for health care in developing countries as well as research for new pharmaceuticals against emerging diseases.

  The Rosy Periwinkle (Catharanthus roseus), called tonga in the south, is used in many regions of Madagascar where it has different traditional uses including  to treat  blood  cancer,  tumors,  diarrhea, 

and even malaria, through use of different plant parts, dosage, and traditional preparation.  Often medicinal plants stems are simply grated into water, or the leaves are employed as a tisane throughout the day, offering effective primary health care that people can afford.  The valorization of medicinal plants and traditional healing offers an incentive for conservation of the primary and secondary forests, the habitats of many important and endangered species, as well as cultural preservation of healing ways.