THE POISON GARDEN website Arum maculatum berries on a Cannabis leaf 


This free script provided by JavaScript Kit

Click for menu of plants in the A to Z section

Rosmarinus officinalis, rosemary


Though harmful only in certain very particular circumstances, which have not been known to arise in modern times, rosemary has an important substance abuse message as well as the most contentious story of all.


Lamiaceae or Labiatae (the Mint family)

Meaning of the Name

Latin ‘ros’, ‘dew’ or ‘water-spray’ and ‘marinus’, ‘sea’. The plant was found on sea cliffs in southern Europe.
From the Latin for workshop or office and, thus, given to the species of a plant which was sold in shops or pharmacies and, by extension, a useful plant.

Common Names and Synonyms


How Poisonous, How Harmful?

The essential oil, used in aromatherapy, can produce miscarriage.


Because aromatherapists are warned of the potential, there are no reported cases of miscarriage.

There are a number of reports of dermatitis arising from handling the plant.

Folklore and Facts

It would be impossible to eat enough rosemary to be harmed but, clearly, misuse of the essential oil could be devastating to a young woman in the early stages of pregnancy. What decides whether rosemary is harmful or not is how we, the human race, choose to use it. In this way, the rosemary has an important message in substance abuse education.

Rosmarinus officinalis, rosemary

Rosmarinus officinalis, rosemary

Rosemary flowers were once white but, while fleeing Herod’s troops, the Virgin Mary draped her cloak over a bush and the blooms took on the blue colour from her garment. This is used to explain the plant's lifespan of no more than 33 years, Christ's time on earth.

Sprigs placed under the pillow were used to ward off daemons and prevent bad dreams. It was woven into brides' bouquets and thrown into graves as a sign that the dead person would not be forgotten.

As well as producing a pleasant smell  burning rosemary was used as a disinfectant.

The phrase 'Rosemary that's for remembrance' is about the second best known quote from 'Hamlet, Prince of Denmark'. This association remains to this day and a sprig of rosemary is used in Australia to remember those killed in war in the way that the poppy is displayed in Britain.

A study conducted by the University of Northumbria looked into the effects of aromatherapy on cognitive function. 144 participants were exposed to the aroma of lavender or rosemary or no aroma and asked to carry out a series of tests widely used for assessing the cognitive performance of Alzheimer’s patients. The study found that lavender caused reduced performance of working memory, and ‘impaired reaction times for both memory and attention based tasks’ whereas rosemary produced ‘a significant enhancement of performance for overall quality of memory and secondary memory factors, but also produced an impairment of speed of memory’.

Aromatherapy is one of the wide range of so-called 'alternative' therapies. Though most, such as homeopathy, reiki and reflexology, have nothing more than a placebo effect, it is possible that there is a physical aspect to aromatherapy. This is based on the negative; that is, everyone accepts that unpleasant smells can produce nausea so it could be that other smells can produce pleasant effects.

It's most telling piece of folklore, however, is simply that rosemary in the garden denotes a house where the woman rules.


The POISON GARDEN website is not connected with Alnwick Garden Enterprises Ltd and/or The Alnwick Garden Trust.


Site Update

All the pages in the A to Z section are regularly updated.

If you've had a personal encounter with a poisonous plant please use the contact form to tell us about it.

A to Z Links

Not familiar with botanical names? Try this common name A to Z converter

Introduction to the A to Z section
Abrus precatorius, rosary pea
Aconitum lycoctonum, wolfsbane
Aconitum napellus, monkshood
Actaea racemosa, black cohosh
Actaea spicata, baneberry
Aesculus hippocastanum, horse chestnut
Amanita muscaria, fly agaric
Aquilegia atrata, columbine
Aristolochia clematitis, birthwort
Artemisia absinthium, wormwood
Arum italicum, Italian cuckoopint
Arum maculatum, cuckoopint
Aspergillus fumigatus
Atropa belladonna, deadly nightshade
Brugmansia suaveolens, angel's trumpet
Bryonia dioica, bryony
Buxus sempervirens, common box
Camellia sinensis, tea
Cannabis sativa, marijuana
Catha edulis, khat
Chelidonium majus, greater celandine
Cimicifuga racemosa, black cohosh
Claviceps purpurea, ergot
Clematis vitalba, old man's beard
Colchicum autumnale, naked ladies
Conium maculatum, poison hemlock
Convallaria majalis, lily of the valley
Cynoglossum officinale, hound’s tongue
Daphne mezereon, spurge olive
Datura stramonium, thorn apple, jimsonweed
Datura suaveolens, angel's trumpet
Delphinium, larkspur
Digitalis spp., foxglove
Dracunculus vulgaris, dragon arum
Echium vulgare, viper’s bugloss
Eranthis hyemalis, winter aconite
Erythroxylum coca, cocaine
Euonymus europaeus, spindle tree
Euphorbia x martinii, red spurge
Euphorbia pulcherrima, poinsettia
Fritillaria spp., fritillary
Galanthus nivalis, snowdrop
Hedera helix, common ivy
Helleborus spp., hellebore
Heracleum mantegazzianum, giant hogweed
Hyacinthoides non-scripta, bluebell
Hyoscyamus niger, black henbane
Ilex aquifolium, holly
Jacobaea vulgaris, ragwort
Juniperus communis, common juniper
Laburnum anagyroides, laburnum
Lactuca serriola, prickly lettuce
Leucojum aestivum, snowflake
Lithospermum officinale, gromwell
Lolium temulentum, darnel
Malus 'John Downie', crab apple
Mandragora officinarum, mandrake
Mercurialis perennis, dog’s mercury
Narcissus, daffodil
Nepeta faassenii, catmint
Nerium oleander, oleander
Nicotiana sylvestris, tobacco
Oenanthe crocata, hemlock water dropwort
Papaver somniferum, opium poppy
Pastinaca sativa, parsnip
Polygonatum odoratum, angular Solomon's seal
Prunus laurocerasus, cherry laurel
Pulsatilla vulgaris, pasque flower
Ranunculus acris, meadow buttercup
Rheum x hybridum, rhubarb
Rhododendron spp.
Rhus radicans, poison ivy
Ricinus communis, castor oil plant
Rosmarinus officinalis, rosemary
Rumex obtusifolius, broad-leaved dock
Ruta graveolens, rue
Salix alba, white willow
Salvia divinorum, sage
Scutellaria laterifolia, Virginian skullcap
Senecio jacobaea, ragwort
Solanum dulcamara, woody nightshade
Solanum melongena, aubergine
Strychnos nux-vomica, poison nut
Symphoricarpos albus, snowberry
Symphytum spp., comfrey
Taxus baccata, yew
Toxicodendron radicans, poison ivy
Thevetia peruviana, yellow oleander
Urtica dioica, stinging nettle
Veratrum album, white hellebore
Verbascum olympicum, Greek mullein
Vinca major, greater periwinkle
Viscum album, mistletoe
Vitex agnus-castus, chaste tree