Indian fig opuntia Opuntia ficus-indica

This cactus, also known as ‘prickly pear’ is cultivated in many parts of the world, including the Mediterranean region, Mexico, Argentina, Brazil, China and Korea. Commercially valuable for its large, sweet fruits the green ‘pads’ are also used in cooking.

Family: Cactaceae

A prickly response to diabetes

Good for us good for the plant

This plant contains fibre and pectin, which can lower blood sugar levels by decreasing the absorption of sugar in the stomach and intestine. Some researchers think that it may also lower cholesterol levels and kill viruses in the body.

One study has found that a combination of insulin and an extract from a related species Opuntia fuliginosa, lowers animals’ blood sugar levels more effectively than insulin alone.

However there is still much more research needed to determine the effectiveness in humans.

Elephant yam Amorphophallus paeoniifolius

Elephant yam (not to be confused with the elephant’s foot yam) is a striking plant with a distinctive flower. The plant is cultivated for its edible tubers, which are an important source of carbohydrate in India and Indonesia, and a valued ‘famine crop’ (used when rice and maize are in short supply) throughout tropical Asia.

Family: Araceae

A natural digestion remedy

Good for us good for the plant

The tubers contain many different chemical compounds and are traditionally used to treat a wide range of digestive conditions, including parasitic worms, inflammation of the bowel, flatulence, constipation and haemorrhoids.

The plant also benefits, as one of the compounds is calcium oxalate, which deters herbivores because of its irritant effects on the mouth and throat.

Fortunatelyhumans have found a way of eating them safely by removing the irritant compound during food preparation.

Pelican flower Aristolochia grandiflora

The pelican flower occurs naturally in the lowlands of southern Mexico and in Jamaica. It has been introduced elsewhere (for example, in the southern USA as a food plant for swallowtail butterflies), and has also become naturalised in parts of Western Australia.

Family: Araceae

Snake bites and antibiotics

Good for us good for the plant

This plant contains many different chemical compounds called alkaloids that act as disinfectants and have also been used as an antidote to snake venom. Research is being done on these compounds to see whether they could be used as an antibiotic.

BenefitsThe plant itself benefits from the presence of the alkaloids, which protect it against attack by insects and disease-causing organisms.

Elephant’s foot yam Dioscorea elephantipes

Have you ever sprained your ankle? Did it swell up? You may have been given cortisone to reduce the inflammation and ease the pain. Cortisone is a hormone with anti-inflammatory properties that is found in the tubers of this plant.

Although there are now cheaper and more viable sources of cortisone, the elephant’s foot yam is still under threat from over-harvesting in the wild for both traditional medicinal uses and the horticultural trade.

Family: Dioscoreaceae

Healing Hormones

Good for us good for the plant

The compounds extracted from the tubers are known as anti-feedants. They taste bitter and can be toxic to animals, so providing excellent protection against predators.

The elephant foot’s yam had not been seen in South Africa since the 1950s.

Howevera population of over 1,000 plants was rediscovered recently, with the aid of a localshepherd, during a special expedition to South Africa involving Paul Smith, head of Kew’s Millennium Seed Bank, and scientists from the National Botanical Institute.