Jimsonweed, Datura stramonium Stems stout, erect, 90-200cm high, usually much-branched in the upper part, smooth and hairless. Larger plants will have a main stem often 5cm or more in diameter. 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. Plants With Spiny Seedpods & Flowers. Curious nature lovers regularly find unusual plants poking up in their own yards or those of their friends and family. A striking vegetative combination like spiny seedpods and flowers is bound to get the attention of an onlooker. Whether you’d like to add more of your …
Jimsonweed, Datura stramonium
Stems stout, erect, 90-200cm high, usually much-branched in the upper part, smooth and hairless. Larger plants will have a main stem often 5cm or more in diameter.
Cotyledons (seed leaves) are narrow and about 2-4cm long, shriveling but persisting on the developing seedling. The first true leaves are ovate with pointed tips and few or no lobes. Later leaves distinctly alternate (1 per node), usually somewhat coarsely and sharply toothed or lobed, 10-20cm long and long-stalked.
Flowers and Fruit
Flowers and seedpods short-stalked, borne singly in the angles between 2 or more stems and a leaf. The calyx is tubular or urn-shaped. The corolla is white or light purple, very long, tubular or trumpet-shaped, 7-10cm long with the flared end having 5 points. The seedpod is at first green and fleshy with sharp, soft spines, becoming a large (2-5cm across), dry, hard seedpod covered with very sharp, harsh spines and containing numerous black, flat, round seeds. Flowers from July to autumn.
Jimsonweed occurs in the warmer parts of southern Ontario in cultivated fields and around farmyards.
It is distinguished by its tall, stout, branched stem (like small trees), large leaves, large, white or purplish trumpet-shaped flowers, large spiny seedpod and sour repulsive odour.
All parts of the plant are poisonous.
Human Health Issues
All parts of the jimsonweed plant are poisonous and are fatal if consumed in high quantities. Its toxicity is caused by tropane alkaloids.
Jimsonweed. A. Top of flowering plant. B. Seedling. C. Fruit.
linear cotyledons of Jimsonweed
A young seedling plant.
Large seedling plant prior to flowering.
The poisonous seeds of Jimsonweed
Table of Contents
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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)
Plants With Spiny Seedpods & Flowers
Curious nature lovers regularly find unusual plants poking up in their own yards or those of their friends and family. A striking vegetative combination like spiny seedpods and flowers is bound to get the attention of an onlooker. Whether you’d like to add more of your newfound plant to the landscape or obliterate it completely, it helps to know what kind of plant you’re dealing with. Several plants sport spiny seedpods and flowers.
Datura innoxia and Datura stramonium are both ornamental plants that grow in Sunset’s Climate Zones 8, 9 and 11 through 31. These 3- to 6-foot-tall perennials boast large, trumpet-shaped flowers and spiny seedpods. Daturas are night-bloomers that release a perfume into the moonlit garden when planted as part of a landscape. Sometimes confused with moonflower, Daturas are in no way related. Datura is a bushy plant related to imsonweed, where moonflower is a climbing vine related to the sweet potato and morning glory. Many Datura plants are poisonous, so take caution in selecting their permanent locations.
Castor Oil Plant
The most dominant feature of castor oil plant (Ricinus communis) is the mass of round, spiny seedpods that erupt after its white stalk-borne flowers begin to fade. In Sunset’s Climate Zones 23 through 28, H1 and H2, it can overwinter and grow into an impressive treelike plant. The rest of the country enjoys the unmistakable castor oil plant’s large lobed foliage during the growing season and sacrifice it to the winter, treating it as an annual in plantings. This plant’s seeds are the source of castor oil, although it is not recommended that you attempt to press your own.
Wild cucumber (Marah macrocarpus) is a beautiful native plant related to gourds, squash, cucumbers and melons. This perennial vine emerges yearly from a massive fleshy tuber and scrambles rapidly before setting delicate, white fuzzy flowers in clusters. The 4-inch-long, egg-shaped seedpod hardens into a spiny fruit containing several black seeds. Although once used as marbles and jewelry by Native Americans, the seeds are bitter and poisonous.
Prickly poppy (Argemone mexicana) thrives with abuse and reseeds itself readily when given the opportunity. The only parts of this 3-foot-tall poppy that aren’t covered in spines or sharp edges are the 1 1/4-inch-wide yellow flowers. Although treacherous, this poppy is often grown in Sunset’s Climate Zones 7 through 43, 2A, 2B, 3A, 3B, H1 and H2. The seeds germinate readily, often when one of the spiny seedpods drops to the ground and shatters.
Other plants with spiny seedpods and flowers that grow wild could be either puncturevine (Triblus terrestis) or California burclover (Medicago polymorpha). Both are considered weedy plants in many Western states. Puncturevine is mat-forming weed with small, oval-shaped leaves on long stems that generally lie along the ground. It sports small yellow flowers and produces razor sharp, spiny seedpods that can puncture bicycle tires. California burclover is a member of the pea family and strongly resembles white clover. However, its three-part leaf is made of three small leaflets, each held on its own short stem. California burclover can grow up to about 2 feet, but generally lies along the ground. Flowers are small and yellow, eventually giving way to seedpods with two or three rows of prickly hooks.