Thorn-appleThorn-apple

Name: Thorn-apple
( jimsonweed, thornapple (thanks to John Vernon for picture of plant and flower) )

Latin name: Datura stramonium L. (D. inermis, D. tatula)

Occurrence: Thorn-apple is an introduced annual weed of cultivated fields, gardens and waste places with a large prickly fruit that gives the plant its name. It is a casual from several sources including birdseed and wool and soybean waste. Thorn-apple occurs sporadically throughout the UK particularly in hot summers. The large trumpet-like flowers are usually white but var. chalybaea has purple flowers.

The plant is poisonous to humans, horses, cattle, sheep, pigs, mules and chickens. Livestock normally avoid it but may be poisoned by eating contaminated hay, silage or seed screenings. Toxicity varies with growing conditions. Thorn-apple has restricted medicinal uses. In Japan, it has been found that an extract of thorn-apple can halt the growth of certain types of brain tumour.


Biology: Thorn-apple flowers from July to October. Seeds mature 30 days after pollination and the seed capsule opens 20 days later. There may be 50 or more capsules per plant, 600-700 seeds per capsule and around 30,000 seeds per plant. Seeds will continue to ripen in capsules on cut down plants. Seeds taken from a partly green capsule that turn black on drying are fully viable. Immature seeds are said to germinate more readily than fully mature seed.

Dead ripe seed may germinate immediately after shedding but the majority soon becomes dormant. The low germination rates are put down to many factors including an impermeable seedcoat. A short soak or rinse in water causes the tissue within the hilum to swell, restricting oxygen uptake and inhibiting subsequent germination. Cracking or chipping the seed coat allows germination to take place.

Burial of seed increases the light requirement for germination to occur. Sensitivity to light and the effect of gaseous diffusion in the soil around the seed allow it to perceive the proximity of the soil surface. Cultivation triggers seedling emergence by the removal of volatile dormancy-inducing metabolites and the exposure of seeds to light. Reburial of seed before germination re-imposes dormancy. In the field, seedling emergence occurred from May to August with peak emergence in May. After emergence, seedlings establish and grow rapidly to shade out surrounding vegetation.

Thorn-apple is a C3 plant in terms of carbon fixation during photosynthesis.


Thorn-applePersistence and Spread: Seeds buried 34 cm deep in soil for 39 years were still capable of 91% germination. The viability of seed buried 8 cm deep remained high for 30 years but then appeared to decrease. Seed in the surface layers of soil decayed faster but viable seeds were still present after 3 years. In dry storage, seed gave 43% germination after 5 years but had lost viability after 15 years.

Mature seeds are dispersed 1-3 m from the parent plant by dehiscence of the seed capsule. This can be stimulated by disturbance of the plant foliage. The capsule and seeds are buoyant in water and can remain floating for 10 or more days. Seeds submerged in water for 6 months still gave 21% germination. The seeds may also be dispersed on farm machinery or as an impurity in crop seeds.


Management: Small patches should be hand pulled before seed is set. Seedlings are readily killed by tillage. Older plants may regenerate from cut down stumps.

In the USA, the beetle (Lema trivittata) causes severe defoliation of thorn-apple and reduces seed production. The fungus Alternaria crassahas been evaluated as a potential biocontrol agent. Thorn-apple seed is moderately susceptible to soil solarization.

A model that simulates population growth following the introduction of thorn-apple, predicts that without adequate control the weed will build up to a high level in 5-6 years.

Updated November 2007.

Further Information / Links:

»UK farmers' case studies

« Back to Annual Broad-leaved Weeds

Comments

  1. This weed arrived in our garden unannounced and unknown and grew to be quite a spectacular specimen - about 4 feet tall. A very good shade plant. Lovely flowers but the plant itself smells foul if touched. Good job the wind blew it down before it seeded! Now that I know it's a weed and can be poisonous I'll be keeping an eye out for it in the future and destroy it before the children notice it.
    - Sarah Russell 8---0-2006

  2. Single plant grew to about 24 inches high in my garden in Leyland Lancashire UK - probably from bird seed. Disposed of after discovery that it was poisonous (grandchildren risk). Thanks to Breda Gater of Shrewsbury for identifying the plant.
    - John D Smith 8---0-2006

  3. We also had a single plant of about 24". We thought at first it was something we had bought from a garden centre. It
    - Terry Paige 8---0-2006

  4. Single plant of about 20 inches seeded in a pot of geraniums, we called it our mystery plant until I discovered what it was.
    It must have dropped from a bird, and seems very happy to grow with one of our geraniums, we will now watch it very carefully and remove it before the seeds drop, we live in Guernsey in the channel islands, so it has probably traveled quite a way .
    - Rose Tinsley 9---0-2006

  5. Single plant of about 20 inches seeded in a pot of geraniums, we called it our mystery plant until I discovered what it was.
    It must have dropped from a bird, and seems very happy to grow with one of our geraniums, we will now watch it very carefully and remove it before the seeds drop, we live in Guernsey in the channel islands, so it has probably traveled quite a way .
    - Rose Tinsley. 5.9.2006 9---0-2006

  6. almost five feet tall with seed cases over four inchs long quickly removed . placed on bonfire .
    - mrs black lincolnshire 9---0-2006

  7. My friend who lives in Kincardine-on-Forth, Scotland, tells me today this plant grew in his garden this year. Wondering what it was he had it identified at the Edinburgh Botanical Gardens. It has been incinerated.
    - John Napier 9---0-2006

  8. I also called this a mystery plant. It has grown to 2 feet tall, with a spread of 3 feet. Lots of seed pods (too many to count). Intend burning soon before any harm is done. Perhaps it's travelled from Lincolnshire to Sculthorpe, Norfolk
    14.09.2006
    - Annette French 9---0-2006

  9. Single plant of about 20 inches, flowers just showing.
    - John B. South Notts 9---0-2006

  10. Found this plant growing on some disturbed soil, recognised it straight away, never thought I'd seen one growing this far north. About 50cm high, flowering and fruiting.
    - Martin McCartan,Co Down 9---0-2006

  11. Have quite a few growing here in herefordshire. Could not identify it untill I saw an article in the farmers guardian which described the plant but showed no picture. Further enquiries led me here. Will pull up and destroy.
    - rosemarie kibble 0---1-2006

  12. One plant in a packet of seeds packed in America didn't know what it was till I found this site.Plant already has about 15 seed pods on it. Will destroy it now.
    - Sylvia S. West Glamorgan 29-09-06 0---1-2006

  13. huge plant appeared in our chicken pen. Identified by our neighbour who's botanist daughter was interested to see the plant fruit. About 10 fruits altogether. Having read
    your article plan to bring cremation forward to now!
    - heather vernon-dier, llandenny, nr usk, gwent 0---1-2006

  14. There have been many more reports of Thorn-apple appearing than usual this year probably because of the very high temperatures we had in the summer.
    - Bill Bond 0---1-2006

  15. My next door neighbour unable to identify this plant in his garden, but said it was very prickly. Found it straight away on this web site. will cut it out tommorow. Thanks for your help.
    - Roy Ashton. lincolnshire 0---1-2006

  16. My next door neighbour unable to identify this plant in his garden, but said it was very prickly. Found it straight away on this web site. will cut it out tommorow. Thanks for your help.
    - Roy Ashton. lincolnshire 0---1-2006

  17. one Thorn Apple plant has appeared on my allotment in Coventry. A nearby allotment has Apple-of-Peru and Gallant and rough Soldier are growing over the whole site.
    - Jeff Brown 0---1-2006

  18. Fantastic Mystery Plant appeared in our chicken pen. 3.5 to 4 foot tall plant, nobody seemed to know what it was. Now enlightened we will not need a guy this bon fire night!!!
    Many thanks. (Devon)
    - Donna Dale 0---1-2006

  19. Appeared in our garden in September. Looks good, so disappointed to learn that it's poisonous. O well, need to find something else for the space!!!
    - S Kennedy West Sussex 0---1-2006

  20. Appeared in my garden and I have just found out what it is from a newspaper article - the article said it is spread from bird seed as the manufacturers are adding it to their mix - I will be writing to the manufacturers to complain!!
    - S Thompson Cheshire 0---1-2006

  21. I noticed it for the first time last year on my allotment. It looked interesting so I let it grow to see what it was. I opened up a seed capsule out of curiosity with seed going everywhere. I have had much more this year and pull it as soon as I see it. It smells horrible.
    - David Bellerby 0---1-2006

  22. Extraordinary plant; thoughy I had bred an original but no. Eventually found out what is is and have now put it on the bonfire.
    - Jonathan Ward 0---1-2006

  23. just discovered what this plant is. Heard about it on radio gardening programme. looked online to find out more. will dispose because of grandchildren and pets
    margaret HULL East Yorkshire
    - margaret walker 0---1-2006

  24. Interesting looking plant, what a pity its poisonous. Identified it from a newspaper article. Thank goodness we did, on closer examination, seed heads were starting to split!
    - W.Lyus, N. Yorkshire 0---1-2006

  25. Appeared in chicken run early October, nearly 6foot tall, with yellow trumpet flowers, which stink at night. large thorned fruit, lovely looking plant. but will destroy it at the weekend, in case it affects my hens. Thank for this imformation.
    - Brian Darling. Northumberland 1---1-2006

  26. Thank you for the information I will keep an eye on any uninvited plants.
    - Debbie Darling, North Wales 1---1-2006

  27. Last March I saw a plant with interesting seed pods that I had never seen before in a front garden in Upton, West Yorkshire. I collected (stole) some seeds and germinated them in seed compost in my green house. I planted on 4 plants in a large pot outside. My plants had lovely pale blue flowers and grew about 3 feet tall. I am so disappointed to find out that the mystery plant is a Thorn Apple and needs to be destroyed as I had planned to scatter the seeds about my garden and to distribute them to friends.
    - Janet Thompson, West Yorkshire 1---1-2006

  28. Turner took tincture of Thorn Apple you know. In mild doses it is a creative if dangerous narcotic.
    - F Tide 2---1-2006

  29. I too had a mystery plant. I sent a picture to a columnist in the EDP but got no answer. Mine may have come from wild bird seed. It appeared on our compost heap in our chickens' area. My husband disposed of it. This was several years ago. I know they have a problem with this in the USA.
    - I. Mehigan, Norfolk 2---1-2006

  30. A beautiful if rather evil-looking plant - exudes an air of fairytale malevolence like no other plant I've ever seen. Saw several plants In italy, ten years or so ago, in a bulldozer-churned patch of wasteland in the hills near Solaio, near Carrara in northern Tuscany - and was mesmerised. A friend here in Oxford says he saw plants come up in a patch of "urban countryside", formerly a corporation tip, when part of it was harrowed to be turned into a sports field in (I think) the early 90s. The tip had last been used, as far as I know, circa World War One. (The sports field was quickly abandoned due to shards of glass coming to the surface! The datura has not to my knowledge been seen again (the land was harrowed again recently but I hadn't the time to go out hunting). (We do however have what I think is the county's only colony of Tragopogon x mirabilis a couple of hundred yards away - must tell the county recorder about that some day...)).
    - Rob Sykes, Oxford 2---0-2007

  31. I can't resist adding that I think it's a bit of a shame that everyone's so eager to pull the thing up.
    I realise it is a potentially dangerous plant, but I can't help thinking that most children old enough to fall foul of it would have an instinct about it, as animals are said to. Then again, I suppose most isn't quite enough. (But it is a beautiful plant...)
    - Rob Sykes, Oxford 2---0-2007

  32. narcotic properties of the plant are discussed in book "The moses legacy" by Graham Phillips
    - t haskins glasgow 4---0-2007

  33. We sent two students by ambulance today as a result of boining the flower to make a tea ...to settle their stomachs.
    Beware!!!! This is a highly dangerous plant that KILLS.
    Some are too young to understand the consequences and teens are using the flowers for a cheap high as it produces hallucinations. They appear to at first have dialated eyes and be under the influence of drugs....but the symptoms become increasingly worse. Thank God they were saved and did not die from the mistake they made. PLANT WITH CARE and be aware of living where teens may take advantage! As a plant owner take respondsibility! If it is accessable to others....like your front yard....GET RID OF IT!
    Nobody's life is worth the beauty of your yard!
    - secret 5---0-2007

  34. handy website for an assignment, it's helped me lots, we have it here too in large quantitie in the farming aeras, a very noxious weed.
    - duncan chris, australia 6---0-2007

  35. I have both the white and purple varieties, of which I save seed every year The latter are very spectacular, reaching four to five feet in height. O.K., so they are poisonous, but is this a reason for eliminating almost half the plant kingdom?
    - Paul Edwin 6---0-2007

  36. Not sure if message 33 is genuine or not but care is obviously needed with all 'poisonous' plants.
    - Gareth Davies 6---0-2007

  37. Many plants have grown up in the last month in a field in St Martin's in Guernsey due to a delivery of topsoil from an unknown source. In view of above comments, if they are not cut down soon before seeding, they might cause a problem in the nearby neighbourhood in future. I will organise!
    Methinks the plant likes global warming plus the surplus of rain we have been having!

    - Michael Deane, Guernsey 7---0-2007

  38. plant appeard in the garden within the vegtable patch and looked interesting so i left it to grow as it appeared to be very unusal.
    4 weeks later it had grown to a height of 20" and was even more interesting now it had flowerd.
    interest now go the better of me so decided to look this plant up (very aware of what do i look for). After a period of time discoverd that i was now in a situation of having a extreamly deadly plant within the veg patch, even more alarming that we have a 4 month old puppy that seams to chew anything in the garden.
    now will decide to uproot and distroy - pity as this is a facinating plant.
    presume that this was a result of bird droppings as we live in a park land area
    - victor de maio, swindon 9---0-2007

  39. I also had this beatiful flower just show up. I emailed my aunt in northern France. She knew what exactly what it was. I have never seen another like here in Mass. My leaves however smell a bit like chocolate. Mine so far is 6 feet tall, equally wide and still growing.
    - Catherine Lacy, Southampton, Mass. U.S.A 9---0-2007

  40. I have a beauty, which I recognised, but am leaving it growing in the chicken run so as to show it to childen and grandchildren with appropriate warnings. The poultry ignore it.
    - J Saunders, SE Monmouthshire 9---0-2007

  41. We have grown a large specimen in North Devon, and it is about to be incinerated....
    - John Pearson 9---0-2007

  42. I photographed my "mystery plant" and it was identified for me today by RHS Wisley - pity it's poisonous, as I've enjoyed watching it grow, and it is filling a gap in poor soil. It is very close to my bird feeders, so assume is must have arrived by bird or in the seed mix.
    - Sue Harris, Guildford, Surrey 9---0-2007

  43. I noticed this plant has grown in my 'new' neighbours garden which has just been turned over and seeded. They have small children and pets so I think I will be a good neighbour and warn them of its potential.
    I remember reading that chemicals from this plant are used in travel sickness tablets.
    - Tim Egleton, Hereford 9---0-2007

  44. I garden for a lady in witnesham, Suffolk. This plant appeared in her garden, but neither of us new what it was. I investigated on the internet and was able to warn her of its properties. It grew to around 3 foot
    - Ian Dunstan 0---1-2007

  45. I grew some great french beans last year 'dwarf' and prolific croppers. Pleased with my returns decided to keep some of the seeds and replant them this year. I've been growing these for the past 3 months and they are now 5ft tall in rows in my veg plot. Clearly not the 'dwarf' variety that I had last year - and no mention on the packet that they were hybrids. Not sure what they were decided to let them grow on.

    I was talking to a gardening friend yesterday and described the plant hoping that they would bear great beans/fruit. But sadly she told me what they were and I found the details on this site.

    I'd like to know how I managed to cultivate these from French Bean seeds??
    - Jill Lewis 0---1-2007

  46. Georgia O'Keefe painted this flower- I was thrilled when it appeared in my garden in New Hampshire, USA. Alas, I have destroyed the plants yearly because of the poisiounous nature, but they always come back- both white and purple. Any suggestions for permanant removal????
    - Lisa 0---1-2007

  47. The picture of the blue and white flower said to be the Thorn apple and the leaves are not that of the Thorn Apple but that of the Shoofly Plant or Apple of Peru. You can quite clearly see the lantern like seed case to the right and behind the blue and white flower.
    Shoofly Plant
    Nicandra physalodes
    Nightshade family (Solanaceae)

    The Thorn apple has a flower like a petunia and does not have the seed cases that are similar to Cape gooseberry. The seeds cases of the thorn apple look like solid green teasels.
    I have a shoofly plant growing in my garden. The most likely source is birdseed.
    Dave


    - David Smith 0---1-2007

  48. We have one enormous Thorn Apple plant and 2-3 smaller
    ones that must have come from bird-feeders. But the flowers on mine are much smaller than in the pictures I have
    seen; same shape but rather puny. But the plant is very
    sturdy, with span of 6ft and a height of only 2-2.5 ft. It shows no sign of autumn.
    - Charles Davidson 0---1-2007

  49. Monster Tree! Watched it grow, tall and strong and wondered about it thinking that some strange critter was going to hatch from the pods...dissected one to analyse the interior...it will have to go now I know it is poisonous!
    thankyou for your help.
    - fiona dunk, bologna, italy 0---1-2007

  50. David- to avoid confusion we have replaced the picture of the flower with a seed pod (which is characteristic). We think that the 'seed case' you refer to in your post above is a flower bud and that the plant is the variety with purple flowers. However, if anyone has good pictures of the flowers please let us have them and we will post them on the page.
    - Gareth Davies 0---1-2007

  51. Found several on Allotment site in East Ham London. Plotholders think it is pretty, I am doing my best to get rid of it.
    - Hazel 3---0-2008

  52. one of my mates have it growing on his farm, he has had it for about 4 years it just showed up out of no where this is the only thing i could really find on it for him... have you got any other ways to kill it???
    - Ryan 7---0-2008

  53. One appeared in my garden and has grown to six inches with one seed pod. I suspect that it came in a growbag. Many plants in the garden are toxic such as the leaves of rhubarb, potatoes, tomatoes so don't be too anxious about it unless you have small children. It is used in medicines and was used in poultices for burns and skin problems.
    - Ron 9---0-2008

  54. I already knew about thjorn apples and when I saw one growing in Holland I told the gardener at the hotel where I was staying about it. It was at least five feet tall and had plenty of fruits on it. It grew from seeds provided for sowing on some rough ground to act as cover and wild animal/bird feed.
    - Derek 1---1-2008

  55. I have a plant that grew to 1.5 mtrs.my chickens ate some of the lower leaves with no ill effects.Bob Flowerdue says the leaves very good for making liquid fertilizer,in the same manner as Comfrey.I will try this out this year, as I saved lots of seed.
    - Roger Sanderson 3---0-2009

  56. we were able to produce a natural termiticide out of thorn apple leaves
    - chegel 3---0-2009

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