Belfast Botanic Gardens
Plants of the medicinal garden
The Global Medicine Garden has a core community of species, just under 160 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 therapeutic uses, to give an idea of the range of properties, not in any way intended as a manual for self-treatment.
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 will be of use to those interested in further enquiry.
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),
--Useful Temperate Plants (https://temperate.theferns.info)
Caution is urged in the use of medicinals, advice from a professional should be sought.
Plan of the Global Medicine Garden
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 such as shortbread, fritters, cordial 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 and the wild garden.
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.
Filipendula ulmaria Meadowsweet: a sacred herb of the Druids. The flowers contain salicylic acid (first isolated from meadowsweet in 1839), later developed into ASPIRIN (from Spirea, the old name for meadowsweet). It is anti-inflammatory, analgesic, tonic.
Achillea millefolium Yarrow: a common plant native to Ireland that is a popular herbal remedy. Well known as a styptic to stop bleeding, it can be used to treat colds and fevers, and is a bitter digestive and anti-inflammatory. NB caution required for large doses, and it can cause sensitivity to sunlight.
Genista tinctoria Dyer's Greenweed: as the name implies, this was valued as a dye plant, producing yellows or green when combined with woad. Medicinally it is stimulant, diuretic, cathartic, diaphoretic. A whole plant decoction was formerly used to treat rheumatism and gout.
Dipsacus fullonum Wild Teasel: a traditional remedy for warts and sores, modern usage has declined. Interestingly, recent studies identified anti-bacterial, anti-oxidant and other potentially therapeutic effects. It has been used to treat fibromyalgia, Lyme disease, cancer and Alzheimer's though, in the absence of more data, it is best regarded as a striking garden specimen, attractive to pollinators.
Primula veris Cowslip: used against the palsy in Medieval times, cowslip has had a long history based largely on its anti-inflammatory, pain-killing and fever-reducing effects. It can be used for insomnia (flowers), for chronic coughs (root) and a multitude of other treatments and could be worth further investigation.
Salvia officinalis Sage: a well-loved culinary herb that 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: 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 both the ornamental or kitchen garden border.
Valeriana officinalis Valerian: a valuable herb still used by herbalists today. With roots rich in valpotriates, it has a sedative action on the central nervous system and is anti-spasmodic. A constituent of many over-the-counter preparations; caution should be exercised in using the herb or such products as they can become addictive if taken over a prolonged period.
Oenothera Evening Primrose: a traditional remedy for multiple ailments from coughs, including whooping cough, to eczema. It is a good source of gamma-linoleic acid, a potential treatment for MS, rheumatoid arthritis, and menstrual disorders, and can help lower cholesterol levels and blood pressure. Along with these beneficial effects it has potential hazards so should be taken under medical supervision.
Origanum vulgare Oregano: this well-known flavoursome culinary herb is also an ancient medicinal for skin sores, digestive upsets, asthma. Recent research has demonstrated anti-microbial and antioxidant activity which may prove useful in cardiovascular and inflammatory conditions. A great plant for the herb garden and for pollinators.
Meum athamanticum Spignel, Baldmoney: principally used as a condiment herb (and cultivated in Scotland for its edible roots), this neat umbellifer has also been used therapeutically as a diuretic and stomachic and for menstrual problems. An attractive highly aromatic plant, whose roots are used to flavour Bavarian schnapps.
Ephedra distachya Ephedra, Sea Grape: 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), all relics of an ancient flora that evolved separately from leafy plants.
Humulus lupulus Hops: mildly sedative so has a long use 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 is 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: a cheery annual/biennial found wild in Europe and commonly grown in gardens. It is anti-inflammatory, anti-spasm (of the digestive tract) and healing to the skin. It (specifically the outer ray-florets) has 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 any garden.
Artemisia abrotanum Southernwood: a woody sub-shrub, evergreen (or ever-grey), aromatic, bitter, an old cottage garden favourite. Used as a culinary and tisane herb in Italy, it is a traditional domestic remedy for improving digestion, as a liver tonic and to expel worms. Antiseptic in its action, it has a delightful 'clean' aroma, and is used in poultices and baths. Caution is needed for internal use: it should not be taken during pregnancy.
Cynara cardunculus Cardoon: this statuesque perennial has edible buds and stalks (usually blanched). It is a bitter herb, containing cynarin which has a raft of medicinal uses: improving digestion (hence the digestive 'Cynar') liver and gall bladder function, lowering cholesterol. The leaves have recent applications in the treatment of chronic conditions such as hepatitus, diabetes, and much more.
Rosa gallica var. officinalis Apothecary's rose: long used for its tonic and healing properties, this gorgeous rose is a must for a delve into pleasures such as spice blend ras-el-hanout, rose water, Turkish Delight, pot pourri. Petals are used internally for colds, bronchitis, depression and externally for sores, eye infections and much more; rosehips are showing the therapeutic potential of their rich source of bio-active compounds.
Salvia rosmarinus Rosemary: an ancient remedy and culinary staple. Active ingredients include essential oils, camphor, borneol, tannins, bitter principle, resin, so it has a wide range of effects: diuretic, antiseptic, spasmodic, digestive etc. It has been used for heart and circulatory disorders, liver and gall-bladder ailments, and externally for muscular aches and pains. Not for use in pregnancy.
Veronicastrum virginicum Culver's Root: 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: 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: 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.
Eupatorium purpureum Sweet Joe-Pye-Weed: a traditional herb of the Native Americans for fevers. Its alternative name gravel-root refers to the use of leaves and roots for urinary complaints such as stones in the urinary tract, and it has applications in treatment of rheumatism and gout. It has similar uses in homeopathy. A statuesque plant for the border.
Liatris spicata Gayfeather: a lovely addition to the border and great for pollinators, this plant of moist prairies is a traditional Native American remedy, used for its analgesic, diuretic, antibacterial and tonic properties. More recently an infusion is used as a gargle for sore throats. The aromatic leaves and roots are used as insect repellant and in pot pourri.
Actaea racemosa Black Cohosh: a first nation North American remedy for 'women's problems' it is still an effective therapy (approved in Germany) for menopausal and pre-menstrual problems. The root has many other attributes: antispasmodic, astringent, cardiotonic, expectorant, sedative, tonic, anti-rheumatic. However, the plant is poisonous in large doses, dangerous in pregnancy, and has a range of side-effects. It is incompatible with alcohol and iron. A treatment best left to the expert.
Parthenium integrifolium Wild Quinine: fresh leaves were used by the Catawbas as a poultice for burns. The flowering tops were a treatment for 'intermittent fevers', hence its use against malaria. The root is diuretic, and one study suggests that the herb stimulates the immune system. NB: may cause allergies or dermatitis in susceptible people.
Silphium perfoliatum Rosinweed, Cup Plant: first nation peoples and early settlers used the plant in a number of ways both as a tea for lung problems, back and chest pain, and as a smoke for head colds and rheumatism. It is not much used in herbalism today and there may be hazards of toxicity. So now a great border plant with a history of medicinal use.
Smallanthes sonchifolia Yacon: a traditional folk remedy from the Andes which 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. The fruit is edible raw or cooked. P. caerulea was a traditional remedy for gastrointestinal problems, and has been examined in vitro for use in inflammatory bowel disease. Not to be taken in pregnancy.
Ugni molinae Chilean Guava, Murta: rich in anthocyanins and phenols, and has antioxidant and antibiotic properties. Recent research is ongoing into medicinal applications. Best known as an attractive 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. Wonderful examples may be seen at Kilmacurragh
Acmella oleracea Electric Daisy, Paracress: a curious plant and a pot-herb, whose leaves may be used raw or cooked, with a distinctive numbing sensation on the tongue. Also known as Toothache Plant, it is used to treat toothache, throat and gum infections. Reputed to enhance the immune system, it has an array of applications including blood parasites and malaria. Research has demonstrated antimicrobial, antibacterial and antifungal activity, thus a promising area for future development.
Crocosmia x crocosmiiflora Montbretia: 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, 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: 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.
Gomphostigma virgatum Otterbush: an attractive silver-leaved riverside plant with starry white fragrant flowers. This has a traditional use for making garden brooms, but is also used medicinally for treating extreme tiredness
Impatiens tinctoria Dyers' Busy Lizzie: traditional in Ethiopia for the treatment of fungal infections, modern studies have demonstrated promising anti-bacterial activity which merits further investigation. Also cultivated as a dye plant and widely grown as an ornamental in both tropical and temperate regions. The tubers yield a red dye for skin, similar to henna, and for dyeing cloth and ink.
Pelargonium sidoides South African Geranium: A popular traditional remedy for gastrointestinal complaints. Recent pharmaceutical work has developed from it a respiratory tract medicine and it has evolved into an international phytopharmaceutical. However the plant has become endangered in the wild due to over-exploitation, and large-scale cultivation needs to be put in place.
Agapanthus praecox African Lily: a traditional remedy for ailments of pregnancy, heart disease, coughs and colds and diarrhoea. The roots are cardiac and stomachic. It has been shown to have anti-inflammatory and anti-oedema activity. Self medication would be unwise as it has shown some toxicity to humans. It is a lovely plant for the garden in late summer.
Catharanthus roseus Madagascan Periwinkle: a traditional remedy. Its content of 'vinca alkaloids' has led to the development of effective treatments for certain forms of leukaemia and Hodgkin's lymphoma. A wide range of ailments has been successfully treated ranging from senility problems to asthma, malaria and dengue fever. A remarkable herb, perhaps better known as an ornamental.
Corymbia citriodora Lemon Eucalyptus: 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: leaves used by Aboriginals 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: 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.
Cordyline australis Cabbage Palm: an Aboriginal remedy for dysentery and diarrhoea, inflammation, cold, earache. A decoction of the roots yields similar amounts of fructose to sugar beet, and is used as a sweet drink. Fibre from the leaves is much used for paper, string, baskets, thatching, even cloth. Simple plant ties can be made from narrow strips of leaf.
Ginkgo biloba 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 (from the less common female tree) 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.
Podophyllum hexandrum 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.
Morina longifolium Whorlflower: 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.
Anemone rivularis River Anemone, Cao Yu Mei: originating from Tibet and the Himalaya. Harvested from the wild for local medicinal use, it has an analgesic action and is used to clean wounds, also coughs and fevers. It is anti-emetic and is also used as an antidote to snakebites and for internal worms.
Physalis alkekengi Chinese Lantern: with a long history as a medicinal, this is diuretic, expectorant, anti-inflammatory, antibacterial and febrifuge. It speeds up urine excretion so is useful in urinary tract diseases, gout and rheumatism. Modern research has demonstrated action on the immune system, cancer, liver and certain hormones. It is a striking plant in the border, though inclined to be invasive, but makes lovely decorative material when the calyces turn orange in late summer.
Ligusticum officinale Senkyu: (formerly Cnidium) with traditional uses in treatment of menstrual disorders, this Umbellifer has analgesic, antibacterial, anti-inflammatory and sedative action. It has been used as a blood purifier and tonic for anaemia and irregular periods. Research has demonstrated inhibition of growth of a wide range of bacteria that suggests further investigation. Its aromatic dried roots have suggested a number of medical and cosmetic applications.
Hydrangea febrifuga (syn. Dichroa) Chinese Quinine: this Hydrangea species is a stalwart of Chinese herbalism, used to treat coughs, colds, bronchitis, fevers, but also cancers and malaria. It has been used as a purgative, limiting its efficiency against malaria where its action is said to be 100 times as powerful as quinine. Research has shown potential in the treatment of autoimmune conditions. An attractive shrub for a warm sheltered situation (protect in winter).
Eleutherococcus senticosus Siberian Ginseng: a traditional remedy in Eastern Asia, China and Japan, used for prevention of colds, flu and general debility. Leaves, roots and berries have all been examined for their chemical content. Its action appears to be more in a protective role, enhancing other treatments and increasing ability to deal with stress, but more clinical studies are needed. The many hazards include incompatability with coffee, unsafe in pregnancy, or for children, adverse heart effects and interaction with other drugs.
Pittosporum tenuifolium 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.
Phormium tenax New Zealand Flax: a valued Maori source of fibre (cf Aboriginal use of Cordyline) 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, antiseptic and healing, akin to Aloe vera.
Pseudowintera colorata New Zealand Pepper, Horopito: 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.
Tetragonia tetragonioides New Zealand Spinach: this plant of the family Aizoaceae was a useful vegetable to settlers. Not a traditional medicine, its rich vitamin and mineral content have led to its use as a support for the immune system, protection of the nervous system, blood clotting and much else. However, its high oxalate content means that it requires blanching and cooking, and over-indulgence should be avoided!
Updates, information on herbs, plant lists and more will follow as the project continues to develop.