Stramonium is derived from the Greek words for mad and nightshade, probably referring to its toxic and hallucinogenic properties.
Common Thornapple - is derived from its fruit as it is a similar shape to an apple and it is covered with spines.
Other names:
Common Thorn Apple
Chameco (Brazil)
False Castor Oil Plant
Jimsonweed (USA)
Prickly Apple
Stinkblaar (S. Africa)
Stramonium.
Summary:
Erect, stout and robust, bushy annual herb with an unpleasant smell. It is 50 cm to 2 metres tall with deeply toothed, egg shaped leaves that are hairless or sparsely hairy with multi-cellular hairs. The white to pale purple, 5 lobed, trumpet shaped flowers are most common in January and February but can occur at any time of year and produce globular, spiny fruit about 4 cm diameter with a circular crown on top.
Description:
Cotyledons:
Two.
Leaves:
Alternate. Unpleasant smell when crushed, Sparsely hairy with non glandular multicellular hairs or hairless. Uppermost leaves in pairs.
Stipules -
Petiole - Slender.
Blade - Dark green, diamond to oval shaped, 40-300 mm long by 30-200 mm wide. Lobes pointed with teeth on the edges near the tip. Edges are usually wavy.
Stems:
Green to purple, erect, branched. 300-2000 mm tall.
Flower head:
Each flower terminates a shoot and the two laterals below grow out to be terminated in another flower, forming a structure with the flowers in the forks of branches.
Flowers:
Trumpet shaped, sweetly scented. Single, bisexual on a short, erect stalk. Close at night or on dull days.
Ovary - 2 celled.
Calyx - Sparsely hairy, 30-50 mm long, 5 ribbed, green tubes with 5 (usually) lobes, that are 6-8 mm long with acute tips and hairy inside. Breaks of just above the base after flowering.
Petals - White to pale purple, 55-100 mm long and 50 mm wide at the top, fused together to form funnel shape. Throat and limb may be folded like a fan, 5, short lobes that are rounded with a point about 10 mm long. Limb folded in the bud.
Stamens - 5, attached to lower half of petal tube.
Anthers - Narrowly oval. Lengthwise slits. White or purple, 3-4mm long.
Fruit:
2-4 celled, oval, erect, spiny capsule, 20-50 mm long by 15-40 mm wide, on a short, erect stalk. Calyx base remains attached as a bent back frill at the base. Opening at the top by 4 valves. 100-200 slender conical spines evenly distributed over the fruit and of similar lengths from 3-16 mm long. Spines are initially soft and become hard as the fruit matures.
Seeds:
Black or grey, many, flattened, kidney shaped, thickened on the edges. 2.5-4.5 mm long. Often wrinkled or finely pitted or with net pattern. 600-700 in each fruit.
Roots:
Strong branched taproot to 1000 mm deep with stringy horizontal laterals that curve downwards. Adventitious roots at the bottom of the stem.
Key Characters:
Petals 55-100 mm long. Fruit with 100-200 spines on an erect stalk. Stamens enclosed in the corolla tube. Black or grey seeds.
Biology:
Life cycle:
Annual. Summer growing. Flowers from February to May. Germinates at any time of the year but prefers the warmer months (20-35deg C) if moisture is available. Grows very fast (eg 2cm/day). It can flower and seed from 2-5 weeks after germination. The plants die as temperatures drop in Autumn and frosts occur.
Physiology:
Reproduction:
By seed.
Flowering times:
January to February in WA.
Most of the year in SA.
Summer in NSW.
Seed Biology and Germination:
Some seeds germinate within 3 days of receiving more than 10 mm rain, if other conditions are suitable. Germination is usually staggered over several months in the field.
Seeds have an after ripening period of 5-11 months.
Cultivation stimulates germination.
Vegetative Propagules:
None.
Hybrids:
Two varieties, D. stramonium var. stramonium with white flowers and green stems, and D. stramonium var. tatula with purple flowers and stems, are recognised.
Hybrids between Fierce Thornapple and Common Thornapple occur.
Allelopathy:
It reduces the growth and germination of barley, linseed, sunflower and wheat.
Population Dynamics and Dispersal:
It is spread by seed, often as a contaminant of agricultural produce. It is also widely spread by flood waters as seed or capsules. Spread by mud on machinery is of lesser importance.
A large number of seeds are set each year. A single plant can produce 30,000 seeds and some may remain viable in the soil for 40 years. Current season seed won't germinate for 5-11 months after it is ripe. Cultivation stimulates germination. Maximum depth for emergence is about 100 mm.
Origin and History:
Central and South America, Europe and western Asia.
The Thugs used it to make the poison Dhat to stupefy their victims and the professional Indian poisoners were called the Dhatuureeas.
First recorded in Sydney in 1802 making it one of the first weed introductions to Australia.
Recorded in Adelaide in 1839 and Tasmania in 1845.
Distribution:
ACT, NSW, NT, QLD, SA, TAS, VIC, WA.
Habitats:
Climate:
Warm temperate and sub tropical regions.
Soil:
Fertile soils with summer moisture.
Often found near stockyards and camps and on alluvial flood plains.
Plant Associations:
Prefers open situations.
Significance:
Beneficial:
They are used in many herbal remedies but injurious side effects are common. In India and Europe they are grown commercially as a source of drugs. Seed extracts have a synergistic effect with organophosphate insecticides.
Detrimental:
Major weed of Cotton, Maize, Mung Beans, Peanuts, Sorghum, Soybean, Sunflower, Tobacco and vegetables.
Weed of summer crops, roadsides, grass lands and disturbed areas.
They compete for moisture, nutrients and light and interfere with harvesting. Some infestations become too dense for stock to penetrate. Similar seed sizes make it difficult to clean Thornapple out of sorghum.
Alternative host for pests and diseases of solanaceous crops such as potato, tomato and tobacco.
Toxicity:
Toxic to stock, especially the seed that have several toxic alkaloids of the atropine group. Human, especially children, deaths have occurred after eating the seeds or nectar. Pulling plants by hand or close contact may cause headache, nausea and dermatitis. Animal deaths are not common because stock avoid grazing it due to its unpleasant odour and flavour. The greatest risk is from seeds in hay, chaff, silage or crushed grain. Poisoning of horses is common but cattle can eat large quantities during droughts with few ill effects. Seed in poultry feed can cause problems. Birth defects have been recorded in pigs after ingestion of Thornapple. Ostrich chicks appear to be very sensitive to poisoning.
All parts of the plant are toxic when both green and dry.
Various extracts are hallucinogenic and used in witchcraft.
Leaves were smoked to relieve asthma but often had dangerous side effects.
Used by some American Indian tribes as a narcotic and hallucinogenic drug in initiation ceremonies.
Honey from the flowers can be toxic.
Tomatoes from plants grated onto Thornapple are also toxic.
Symptoms:
Dryness of the mouth, difficulty swallowing and speaking, high temperature, coldness of the extremities, dilated pupils, poor vision, nausea, vomiting, excitability, delirium, depression, coma, weak and rapid pulse, slow irregular and weak breathing and death from respiratory failure.
Headache, nausea and dermatitis may occur in people working with or hand pulling plants.
Treatment:
As for atropine poisoning.
Remove stock from infestations. Don't expose hungry stock to infestations with little other feed. Don't feed crushed grain containing Datura seeds to stock or poultry.
Don't allow children to play with fruits.
Legislation:
Noxious weed in all mainland states.
Management and Control:
Imported seeds of summer crops such as sorghum, Sudan grass and maize or bird seed should be checked carefully for Datura seed. Contaminated seed should be sent to the Department of Agriculture to determine the source of contamination.
Small infestations can be removed mechanically and burnt before seed is formed. Larger areas can be repeatedly cultivated before flowering. Cultivating large plants is often ineffective. Hormone herbicides are only effective on small vegetative plants. Glyphosate, paraquat, diquat and atrazine provide good control of young plants. Selective herbicides are available for a number of crops.
Thresholds:
Eradication strategies:
Herbicide resistance:
Biological Control:
The Three lined Potato beetle (Lema trilineata) often defoliates Thornapple.
Related plants:
Fierce Thornapple (D. ferox)
Downy Thornapple (D. innoxia)
Native Thornapple (D. leichhardtii)
Hairy Thornapple (D. wrightii)
Hoary Thornapple (D. metel)
D. candida (Brugmansia candida)
Plants of similar appearance:
Four introduced and one native annual Datura species are referred to as Thornapple. These are distinguished on leaf and fruit size and shape and the type of spines in the fruit.
Fierce Thornapple has less spines on the fruit, 40-60 rather than 100-200, shorter petals and the seeds are larger.
Downy Thornapple has densely hairy leaves and larger flowers, larger fruits with brown seed and the stigma is shorter than the anthers.
Native Thornapple has smaller flowers.
Hairy Thornapple has yellowish seeds and the stigma is taller than the anthers.
Castor Oil plant has similar fruit but is a much larger plant growing to the size of a small tree.
Brugmansia potato, tomato, tobacco, petunia.
References:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P224. Photos.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P755.
Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P317, 319.
Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P586. Diagram.
Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P634.
Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P167-72. Diagrams.
Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P218-219. Diagram. Photo.
Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).
Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). # 415.6.
Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P529.