Datura, a night-blooming flower sometimes raised in home gardens, is also known as Jimsonweed or Thornapple (Datura stramonium). Jimsonweed is a contraction of Jamestown and is the name that early settlers and British soldiers gave the plants. Thornapple is an appropriate common name because it aptly describes the … Thorn apple is a weed that prefers a warmer climate than Britain, but in hot summers they are quite commonly found. Another common name, devil's snare, sounds alarming, but a few simple precautions will enable gardeners to handle this weed without great risk.
What Weed Has a Round Prickly Seed Pod?
Datura, a night-blooming flower sometimes raised in home gardens, is also known as Jimsonweed or Thornapple (Datura stramonium). Jimsonweed is a contraction of Jamestown and is the name that early settlers and British soldiers gave the plants. Thornapple is an appropriate common name because it aptly describes the round, prickly seedpod that develop after the spent flowers fall off the plant. The prickly seedpods prevent animals from eating the toxic seeds.
Jimsonweed grows to heights of between 1 and 5 feet. Its leaves’ edges are toothed edges and nearly egg shaped with pointed ends. Their length ranges from 2 to 8 inches. Funnel-shaped flowers are 2-1/2 to 4 inches long and open to a trumpetlike bell in white, violet or lavender. The plant’s fruit is a spiny pod measuring roughly 2 inches in diameter. The seedpods grow as they ripen and the seeds mature. Ripe seedpods burst open, scattering the seeds.
- Jimsonweed grows to heights of between 1 and 5 feet.
- Its leaves’ edges are toothed edges and nearly egg shaped with pointed ends.
Most species are low-growing, shrublike or spreading perennials or are prolifically reseeding annuals. D. wrightii is the species that is common to the Western United States. Rank-smelling leaves and large, white flowers that are occasionally tinged with purple characterize this plant. A sprawling perennial, the plants have enormous taproots that may extend deeper than 2 feet into the ground. Its geographic range extends from California to Utah, Arizona, New Mexico and into Texas. D. wrightii is considered a cosmopolitan annual weed that seeds prolifically. D. discolor is a native species found in riverbeds and desert washes in Arizona and southeastern California. It has smaller flowers. D, stramonium is naturalized throughout the United States. D. stramonium is distinguished from D. wrightii because the plants have smaller flowers and a more erect growing habit.
- Most species are low-growing, shrublike or spreading perennials or are prolifically reseeding annuals.
- D. discolor is a native species found in riverbeds and desert washes in Arizona and southeastern California.
The contraction of “Jamestown weed” is the origin of the name Jimsonweed. Soldiers and settlers were poisoned after eating the plant’s leaves in salads. Long ago in India and Russia, robbers would grind up the seeds of Jimsonweed and mix them with water as a way to sedate, induce amnesia or daze people they intended to victimize and rob. Members of the ancient Indian religious order that worshipped Kali, the goddess of destruction, would also grind the seeds and feed them to people before robbing and/ murdering them. In China, Jimsonweed was prescribed for the sedative effects, for foot diseases and used for flatulence.
All parts of Datura or Jimsonweed are poisonous. Keep places where livestock graze free of the plant. Ridding an area of plants is difficult and time consuming because of the ease with which seeds spread. Some people may experience skin irritation from contact with these plants, so wear protective clothing or gear. Symptoms of Jimsonweed poisoning include blurred vision, confusion, dilated pupils, dry mouth, difficulty urinating, hallucinations and tachycardia. Although it rarely causes death, later signs of toxicity may include coma and seizures. Emergency medical attention is necessary in cases of suspected Jimsonweed poisoning. Poisoning is treated with activated charcoal and gastric lavage. Severe sinus tachycardia is treated with beta-blockers.
Datura stramonium (thorn apple)
Thorn apple is a weed that prefers a warmer climate than Britain, but in hot summers they are quite commonly found. Another common name, devil’s snare, sounds alarming, but a few simple precautions will enable gardeners to handle this weed without great risk.
Latin name Datura stramonium
Common name Thorn apple
Life cycle Annual
Areas affected Uncultivated ground, beds, borders
What is Datura stramomium
Datura stramonium (or thorn apple as it is commonly known) is an annual weed of gardens, roadsides and other waste or cultivated land. It is widely naturalised in warmer countries throughout the world, and is quite common in the British Isles, often appearing in waste and cultivated ground.
Although quite a striking plant, it is as well to be aware that all parts, particularly the seeds, are highly poisonous. It belongs to Solanaceae, a family which includes the potato and tobacco, and many members of this family contain toxic substances. This page looks at options for gardeners when Datura stramonium is becoming a problem.
This weed can grow to heights of 1m (3¼ft). It flowers from July to October with wide, funnel-shaped flowers. These are usually white but plants with purple or lilac flowers and purplish stems are referred to as Datura stramonium var. chalybaea (syn. D. stramonium var. tatula).
It produces seedpods which are large and spiny (hence the common name thorn apple) though plants with spineless seedpods are known and these are referred to as D. stramonium var. inermis.
The leaves very broad and coarsely toothed.
The potentially harmful poisonous and hallucinogenic properties of this plant can sound alarming especially when made much of in the media. The leaves and seed pods also look exotic and alien. In fact this is quite a small plant and not very invasive in Britain. Common sense precautions limit risk factors so that gardeners need not be too alarmed by this weed.
The seed appears to retain its viability for many years when buried and germinates when the soil is disturbed. Spread is facilitated by human activities – in gardens it appears to be a contaminant of birdseed.
The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.
There are a number of non-chemical control options.
Dig, pull or hoe out plants before seed is set. Seedlings and plants that have not set seed can be added to the compost heap where the toxins will naturally break down. However, plants that have set seed should be consigned to the green waste collection, buried deeply (60cm/2ft or more) or burnt in order that the seed does not disperse in the garden or persist in the compost heap. Always wear gloves or thoroughly wash hands after handling this plant.
Use a mulch of organic matter, at least 5cm (2in) thick or opaque sheeting, such as woven polypropylene, to smother this weed.
Contact herbicides such as acetic acid (eg. Weedol Gun! Fast Acting, Roundup Speed Ultra, Spot On Fast Acting Weedkiller or Resolva Fast Weedkiller), fatty acids (eg. Job Done Garden Ultrafast Weedkiller) and pelargonic acid (eg. Doff 24/7 Fast Acting Weedkiller, Roundup NL Weed Control or Resolva Xpress Weedkiller) are good at knocking back young annual weeds such as thorn apple. Systemic herbicides such as glyphosate (e.g. Roundup Fast Action, SBM Job done General Purpose Weedkiller or Doff Advanced Concentrated Weedkiller) will also be effective and can be used when mature plants need to be eliminated.
These herbicides are non-selective and so care should be taken while spraying near other plants. Plants to be avoided can be covered with a bucket/flowerpot or screened with plastic when spraying.
Inclusion of a weedkiller product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener.
Weedkillers for gardeners (Adobe Acrobat pdf document outlining weedkillers available to gardeners; see sections 3a and 4)