These Madagascan plants have the power to save lives

In Malagasy markets, sundews are sold as cough treatments and vanilla orchids as aphrodisiacs. 

Malagasy people have been using Madagascar’s unique native plants for food, medicine and handcrafts for thousands of years. Their knowledge of these plants is encyclopaedic and many Malagasy feed their families and send their children to school by selling plants they harvest from the wild.  

Scientists from Kew Madagascar – RBG Kew’s third research site, based in Antananarivo - are working with the global wildlife trade NGO, TRAFFIC, to find sustainable ways to use Madagascar's diverse plant life and invaluable local knowledge. 

They’ve scoured local markets to see what’s for sale and what each plant is used for, then measured plant population sizes across Madagascar so that decision-makers can encourage the legal and sustainable use of Madagascar’s plants without endangering them.  

We’ve collected six of their fourteen fascinating findings. The Kew team's full report will be out later this year - in the meantime, find out how TRAFFIC is working to protect Madagascar's unique plant life.

Madagascar periwinkle (Catharanthus roseus) 

Endemic to Madagascar, this shrub with its eye-catching pink flowers is well known for fighting cancer. It produces the alkaloids vinblastine and vincristine, which are used in chemotherapy to treat leukaemia, breast cancer and Hodgkin’s lymphoma. 

Long before Western medicine discovered the periwinkle’s anti-cancer abilities, Malagasy people were using it to manage diabetes: studies have shown an extract from its leaves can lower blood glucose levels. It’s also used to help reduce blood pressure, and as an antibacterial and antifungal treatment. 

This essential plant is thriving in Madagascar and around the world as both a beloved garden plant and a weed. One study called it “almost invulnerable”. 

You can see Madagascar periwinkle at Kew in the Princess of Wales Conservatory. 
 

Giant baobab (Adansonia grandidieri) 

Known as ‘the mother of the forest’ in Malagasy, every part of the giant baobab tree has been used by locals for generations – the bark and leaves can reduce a fever; cooking oil is extracted from the seeds; and the wood and fibrous bark are used as building materials. 

Classified as an endangered species, the giant baobab is found only in Madagascar. During the rainy season it stores water in its gigantic trunk, with one tree known as ‘Tsitakakoike’ growing a whopping 27 metres in circumference (or: 8.7 metres in diameter). 

In the dry season the baobab produces huge white flowers that open only for a single night, releasing the scent of sour watermelon to attract their pollinators: moths, bats and lemurs.

Sundew (Drosera madagascariensis) 

Did you know that this carnivorous garden-centre plant can also be used to treat a cough?  

The sticky, droplet-coated tentacles that give the sundew its common name are perfect for catching the plant’s insect prey. They also contain chemicals that relax muscles and reduce phlegm, so infusions are often used to treat coughs and other respiratory illnesses. 

Drosera madagascariensis is just one of 194 species of sundew, which are found in wet and boggy areas across the world. This one is native to Madagascar. Every month, the international market demands five tonnes of exported sundews. 
 

When we lose a species, we could be losing invaluable resources we never got the chance to understand. We can’t afford to lose precious plant species, but protecting plants should not come at the cost of increasing Malagasy poverty: it should be a chance to partner up with the people who know these plants best so that all of humanity can benefit.