Belfast Botanic Gardens
Plants of the medicinal garden
The Global Medicinal Garden has a core community of species, just under 150 species in total at the time of writing. Additional plants will vary from year to year and season to season. The garden is divided into geographical zones which are shown on the plan below. We illustrate here some iconic medicinal plants from each zone, and the catalogue will become more comprehensive over time.
The notes are a brief overview of the herbs and their medicinal uses, not in any way intended as a manual for self treatment. Caution is urged in the use of medicinals, advice from a professional should be sought.
Multiple sources have been used in compiling this catalogue, ranging from notes from a course for professionals, lectures, visits and practical classes at the wonderful Chelsea Physic Garden, with additional books and field guides plus online data from a selection of reliable websites (see below), which may be of use to those interested in further reading.
Chiej, Roberto The Macdonald Encyclopedia of Medicinal Plants, Macdonald
Summer, Judith The Natural History of Medicinal Plants, Timber Press 2000
Foster, Steven and Duke, James A.,1990, A Field Guide to Medicinal Plants, Eastern and Central North America, Peterson Field Guides
Good sources for accessing further information online are: Plants for a Future, https://pfaf.org
Plan of the Global Medicinal Garden
skip forward to individual areas -
- where we can manage, herbs of native origin have been planted
Sambucus nigra, Elder, a 'pharmacy in a plant'; every part of the elder has been used in traditional medicine: leaves to stop bleeding, flowers for fevers, berries for colds. Recipes abound for culinary uses and country wines.
Iris pseudacorus, Yellow Flag, emetic and astringent, this is not one for home remedies. The sliced rhizome was an old remedy for toothache. Today it is valued as a riverside or pond plant.
Digitalis purpurea, Foxglove. The beauty of this common wild flower and its relatives belies their importance in pharmacy, although stories and legends abound on its magical properties. A traditional remedy that in modern times has provided an impressive array of heart drugs: Digoxin, Digitalin, Gitalin among others.
Salvia officinalis, Sage. This well-loved culinary herb has many medicinal applications, (salvere means to heal). It is antiseptic, anti-inflammatory, reduces blood sugar, and is used for tonsillitis and oral health.
Betonica (Stachys) officinalis, Betony had countless uses in Medieval times; it was a panacea. Today the leaves are used to cleanse and heal cuts and grazes, and in homeopathy for asthma and excessive perspiration.
Foeniculum vulgare, Fennel, is a time-honoured remedy for coughs, bronchitis, flatulence and loss of appetite. Fennel is also a popular ingredient in the kitchen and is valued in distilleries and perfumeries for its distinctive aroma and flavour. It is an attractive plant, great for pollinators, in the garden border.
Ephedra distachya, Ephedra (sea grape), is the source of the drug ephedrine, an antihistamine used, for example, as a nasal decongestant in asthma, hay fever and common cold. An interesting plant, Ephedra is a gnetophyte (like Gnetum and Wellwitschia), relics of an ancient flora that evolved separately from leafy plants.
Humulus lupulus, Hops, is mildly sedative so is used for insomnia. It also reduces high temperature and aids digestion. It is perhaps better known for its widespread use as a bittering agent in beer. An anaphrodisiac, this does not appear to deter beer-drinkers.
Hyssopus officinalis, Hyssop. An infusion of hyssop can be used for coughs, bronchitis, and excessive perspiration. Best left to the professional herbalist, it is contraindicated in a number of conditions including pregnancy and some nervous conditions. The essential oil is used in perfumes (Fougere, Chypre) and in some liqueurs.
Calendula officinalis, English Marigold, is a showy annual found wild in Europe and commonly grown in gardens. It is anti-inflammatory, anti-spasm (of the digestive tract) and healing to the skin. The outer ray-florets have been dubbed 'Poor man's Saffron' for its culinary use in colouring and flavouring dishes such as risotto or fish stew. Altogether a must for the garden.
Veronicastrum virginicum, Culver's Root, was an old herbal remedy used by several native American tribes as a strong laxative, to promote sweating or to stimulate the liver. It also served as an emetic and diuretic. Great care had to be exercised in both preparation and administration to avoid over-dosing. In particular, the fresh root is potentially toxic, so definitely one for the experts.
Echinacea purpurea, E. angustifolia, Echinacea was a key multi-action herb for North American Plains Indians who used it for snake-bites, cancers, toothache, colds, flu and other ailments. Recent studies have confirmed its action as an immune-system stimulant and supported its use in Europe for herpes, throat infections and in cold and flu prevention.
Mahonia aquifolium, Oregon Grape is a spring-flowering evergreen shrub that produces blackcurrant-sized edible fruit. Used by several native American tribes as a general tonic, it is valued for its beneficial action on digestive problems, gastritis and gall-bladder problems, and in addition has been used as a gargle, mouthwash and for bloodshot eyes. It contains Berberidine which has noted antibacterial action. The berries are gently laxative. Best avoided in pregnancy.
Smallanthes sonchifolia, Yacon, a traditional folk remedy from the Andes has become popular in UK and Europe as an esoteric vegetable. It is a source of sweeteners that are useful in the management of diabetes. Extracts of the roots have prebiotic activity, promoting healthy gut flora. The leaves have anti-inflammatory activity. Research is ongoing into the application of active principles from yacon in prevention of disease.
Passiflora caerulea, Passionflower
P. edulis, the species most commonly used medicinally, is a traditional herb used for its sedative action. It is still a popular remedy used for insomnia, anxiety and related conditions. Externally it has been used as a poultice for sores and inflammation. Not for use in pregnancy.
Ugni molinae, Chilean guava or murta is rich in anthocyanins and phenols, and has antioxidant and antibiotic properties. Recent research is ongoing into medicinal applications. Best known as an attractive dwarf shrub that bears pretty pink bell-like flowers and berries with a delicate strawberry aroma and flavour. Widely described as Queen Victoria's favourite fruit, it is delicious raw, or made into jams or confectionery.
Crocosmia x crocosmiiflora, Montbretia, is an ornamental that has naturalised widely. C. aurea its parent was a traditional remedy in E. Africa for malaria and arthritis. The flowers produce a yellow dye used as a saffron substitute. In vitro studies demonstrate anti-microbial and anti-tumour activity that merit further investigation.
Zantedeschia aethiopica, Arum or Calla lily, a beautiful ornamental and popular florist's flower, has a myriad of traditional medicinal uses: for boils, burns, inflammation, rheumatism and gout. Pharmacological studies have shown anti-bacterial, anti-fungal, antioxidant and antihistamine action, clearly indicating the potential for further evaluation.
Tulbaghia violacea, Society garlic is an edible plant raw or cooked like a mild garlic. Traditionally a Zulu remedy for respiratory ailments, intestinal worms, it is also used around the home to repel fleas, ticks, moles and snakes due to its pungent smell.
Corymbia citriodora, Lemon eucalyptus is grown for timber and for essential oil. Its leaves are an Aboriginal remedy for respiratory ailments and skin infections. The oil is used in gargles and inhalants. Extreme care is needed; large amounts are toxic. A substance akin to manna scraped off the leaves is eaten like honey.
Eucalyptus globulus, Blue Gum. Aboriginals used the leaves for fungal infections and wounds. It is the main source of the powerfully antiseptic eucalyptus oil, used in mouthwash, throat lozenges and other preparations for colds, and as a topical balm for bruises, sprains, backache. Extracts are used in laundry products, soaps and perfumes. Caution: do not ingest the oil.
Tasmannia lanceolata, Tasmanian pepper, was an Aboriginal remedy for skin disorders, colic, stomach-ache. Anti-scurvy like its relative Drimys winteri, its antimicrobial activity shown in vitro indicates potential to combat disease and food spoilage. The spicy fruit is pleasantly edible, it and the seeds are used like pepper.
, Ginkgo, maidenhair tree. Now endangered in the wild, the distinctive leaves of ginkgo have been used as traditional medicine for respiratory, circulatory and brain disorders in China. The nuts are eaten in Japan and also used medicinally. Current research continues into its use for Alzheimer's disease and dementia, cardiovascular disease and a host of other disorders.
Himalayan mayapple. A traditional medicine used as a purgative, for healing and anti-tumour properties, this species has shown high activity in modern cancer studies (Etoposide is approved by FDA), and research is ongoing. There are multiple serious side-effects, so it has to be regarded as highly toxic. It is endangered in the wild, and is in need of conservation and cultivation measures.
, Whorlflower. A handsome evergreen with spiny leaves whose flowers are moth-pollinated, this is an important traditional Tibetan medicine used to support the digestive system. The root extract is antiseptic and has been used to treat burns and wounds. The essential oil, used in perfumery, has shown antimicrobial activity and has potential for future medicinal applications.
, Kohuhu. Well-known as a garden evergreen and as floristry foliage, this was a traditional Maori medicine. Both resin and leaves were used topically for skin diseases or for poultices. The resin was an ingredient of gums to chew for bad breath. Recent work has indeed demonstrated antimicrobial action, and research has explored the chemistry of the very rich content of volatile compounds.
, New Zealand flax (seen here naturalised in the West of Ireland), is a valued Maori source of fibre useful for items ranging from baskets and hats to bandages, twine, even cloth and paper. Traditional uses as medicine have been recorded for the gel-like substance in the leaves, akin to Aloe vera.
, New Zealand pepper (Horopito), was a traditional Maori remedy for wounds and ringworm, while settlers used it to treat diarrhoea, and the bark as a substitute for quinine. Indeed there are many reported uses as the plant is rich in biologically active substances, so there is much scope for further research.
Updates, information on herbs, plant lists and more will follow as the project continues to develop.