Medicinal plants images
Discover some of the plants – ranging from the everyday to the obscure – that have been used to treat human illness
1. Rose flower
As well as being symbolic of love, romance and beauty, roses have many medicinal uses and health benefits. Rose water is used to flavour foods, while rose petals and rose hips (the fruits of the rose plant) are commonly used in herbal teas and remedies. Roses are thought to have astringent and anti-inflammatory properties.
2. Thuja tree seed head
Thuja occidentalis is a European tree believed to have natural antimicrobial properties. In folk medicine it has been used to treat cystitis, psoriasis and rheumatism among other conditions. Today it is mainly used in homeopathy in a variety of preparations for wart removal, thrush and ringworm. This image is a scanning electron micrograph of a thuja tree seed head.
CC BY NC Annie Cavanagh/Wellcome Collection
3. Spiral aloe
This plant, Aloe polyphylla, is native to the Maluti mountains in Lesotho and was discovered in 1915. It has a striking physical appearance, characterised by the unique, symmetrical five-pointed spiral arrangement of its leaves, which point either clockwise or anticlockwise. It is used to treat skin complaints.
CC BY brewbooks/Flickr
4. Teasel bud
Teasels are thistle-like wildflowers. Teasel-root tea was once used to stimulate appetite, reduce fluid retention and help some liver complaints. The regular patterns of spines and flowers seen in this teasel bud are controlled by the same family of genes that controls the layout of animal and human bodies.
5. Pine wood
Pine wood is a source of pine resin, which is used in traditional medicine and in the production of turpentine. A substance called ecabet sodium can be extracted from pine resin and is used in the treatment of gastric ulcers, oesophageal reflux and dry eye syndrome. The image above is a composite image of a pine trunk cross-section taken under a light microscope at magnification 40x.
6. Betel leaves
Paan ka patta, known as betel leaf (Piper betle), is said to have originated in India, where it is considered to have valuable medicinal and cultural properties. When chewed it acts as a pain reliever and anti-inflammatory agent, and it can help reduce plaque formation on teeth. However, it is also often chewed together with tobacco and other ingredients in an addictive psychostimulating mix, which can have negative health effects.
CC BY Ed Clayton/Flickr
7. Smooth flatsedge
Smooth flatsedge (Cyperus laevigatus) is indigenous to Hawaii, where it is also known as makaloa. Makaloa fibres can be used to remove impurities from medicinal liquids, and it was also traditionally crushed into a powder for treating head colds, deep cuts, boils, skin ulcers and other skin disorders.
CC BY David Eickhoff/Flickr
8. Calico flowers
Calico flowers (Aristolochia elegans) can be used to treat stings or bites from venomous animals. Notably they have been used in Mexico, where venomous animals such as scorpions pose a particular threat.
CC BY NC ND jennyhsu47/Flickr
9. Noni fruit
Noni (Morinda citrifolia) has been used in folk medicine by Polynesians for over 2,000 years. Hawaiians believe that it helps fight diabetes, high blood pressure, abnormal growths and other chronic disorders. Research has shown that a polysaccharide-rich substance found in noni juice attacks abnormal cells and stimulates the body’s immune system.
CC BY Scot Nelson/Flickr
10. Red passion flower
Passion flowers consist of around 400 species of the Passiflora genus, which are mostly vines. Certain flowers are used to treat sleep disorders, pain, insomnia and nervous exhaustion – although research into the flowers’ medical uses has been limited.
CC BY NC ND jennyhsu47/Flickr
11. Hibiscus flower
Flowers of the Hibiscus genus, first found in Angola, can be used to treat medical conditions including colds, heart and nerve diseases, inflammation, stomach irritation, disorders of circulation and loss of appetite. Hibiscus tea – known for its sour taste – is also enjoyed across the world.
CC BY NC ND Annie&John/Flickr
12. Tree heliotrope
Tree heliotrope (Heliotropium foertherianum), also known as octopus bush, is common throughout Polynesia, Micronesia, Melanesia and the Indian Ocean region. It plays a significant role in the traditional medicine and ritual cultures of the islands where it is native, and is thought to have antiviral, antibacterial, antioxidant and anti-inflammatory properties.
CC BY NC sleepychinchilla/Flickr
13. Wild ginger
Wild ginger (Asarum candense) is a North American plant whose medicinal qualities were known to many Native Americans. It was used to make infusions thought to bring on menstruation and cure an irregular heartbeat. Its large heart- or kidney-shaped leaves are hairy, dark green and deeply indented at the stem.
CC BY NC ND Pictoscribe/Flickr
14. Coral tree
The coral tree, or Erythrina crista-galli, is a small, spiny tree that can grow 6–10 metres tall. In traditional medicine its bark was used to treat rheumatism and hepatitis, and it could also be gargled to treat a sore throat as part of an infusion or applied as a wash to treat cuts.
CC BY NC Gabriela F Ruellan/Flickr
15. Chinese flower
This plant, Paederia scandens, is known as Chinese flower in English and is found in the Himalayas up to an altitude of 1,800 metres. It is used in folk medicine for treating a number of ailments, such as rheumatism, paralysis, abscesses, gout, diarrhoea, dysentery, infertility, colic and flatulence.
CC BY NC ND jennyshu47/Flickr
Image research and captions by Annelise Andersen and Natalie Hunter.
Related resources
Real Voices: Martin Cheek
Olivia Kersey interviews Martin, a researcher at Royal Botanic Gardens, Kew, looking for new plant species
Real Voices: Pippa Greenwood
Horticultural broadcaster and writer
Plants that changed the world: cinchona
Tom Freeman looks at the Peruvian tree that gave us the first effective treatment for malaria – as well as a refreshing drink