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Conium maculatum - L.

Common Name Hemlock, Poison hemlock
Family Apiaceae or Umbelliferae
USDA hardiness 4-8
Known Hazards A very poisonous plant, the toxins are especially concentrated in the seed[1, 7, 10, 19, 62, 76]. The stems contain up to 0.06% of the toxic alkaloids, the leaves between 0.03 and 0.8%, the flowers from 0.09 to 0.24% and the green fruit from 0.73 to 0.98%[240]. The toxins, however, are very volatile and decompose readily[65], especially when the plant is dried or cooked[4]. The toxins paralyse the respiratory nerves, causing death by suffocation[238]. Children have been known to die after using the hollow stems as blowpipes[200]. The poisonous nature of the plant varies considerably, with many people believing that the plant is less toxic when grown in cooler climates[268].
Habitats Waste ground and in damp places, avoiding acid soils and heavy shade[7].
Range Europe, including Britain, from Norway and Finland south and east to N. Africa and Iran.
Edibility Rating    (1 of 5)
Other Uses    (0 of 5)
Weed Potential Yes
Medicinal Rating    (2 of 5)
Care (info)
Fully Hardy Moist Soil Semi-shade Full sun
Conium maculatum Hemlock, Poison hemlock

Conium maculatum Hemlock, Poison hemlock


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Physical Characteristics

 icon of manicon of flower
Conium maculatum is a BIENNIAL growing to 2 m (6ft) by 1 m (3ft 3in).
See above for USDA hardiness. It is hardy to UK zone 5 and is not frost tender. It is in flower from June to July. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

UK Hardiness Map US Hardiness Map


Plant Habitats

Woodland Garden Dappled Shade; Shady Edge;

Edible Uses

Edible Parts: Leaves
Edible Uses:

Leaves - cooked[105]. Although toxic, plants found in the south of England are comparatively harmless and the leaves are used as a pot-herb[2]. They can also be dried for later use. The toxic principle is said to be destroyed by thorough cooking or drying[4, 100]. Caution is advised, especially on the remarks about plants in southern England[K]. See the notes above on toxicity.

References   More on Edible Uses

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.
Analgesic  Antirheumatic  Antispasmodic  Cancer  Emetic  Epilepsy  Galactofuge  Homeopathy  

Hemlock is a very poisonous plant that has a long history of medicinal use, though it is very rarely used in modern herbalism[238, 254]. It is a narcotic plant that sedates and relieves pain[238]. The plant contains coniine, an extremely toxic substance that can also cause congenital defects[254]. The whole plant is analgesic, antispasmodic, emetic, galactofuge and sedative[4, 7, 9, 21, 213, 222]. It is a traditional folk treatment for cancer[222] and was formerly widely used internally in very small doses to treat a variety of complaints including tumours, epilepsy, whooping cough, rabies and as an antidote to strychnine poisoning[232, 254]. It is still used externally, usually in ointments and oils, in the treatment of mastitis, malignant tumours (especially breast cancer) anal fissure and haemorrhoids[238]. The leaves and stems should be harvested when the first fruits are forming, since they are then at their most active medicinally[4]. The fruits are gathered either when fully ripe, or before they turn from green to yellow, and are then dried[4]. Because of the extremely toxic nature of this herb, it is seldom employed nowadays[232]. Use with extreme caution and only under the guidance of a qualified practitioner[21, 238]. See also the notes above on toxicity. A homeopathic remedy is prepared from a tincture of the fresh plant, harvested when in flower[232]. It is used for treating complaints such as dizziness, coughs, insomnia, exhaustion[232], arteriosclerosis and prostate problems[7].

References   More on Medicinal Uses

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Other Uses

None known

Special Uses

Scented Plants

References   More on Other Uses

Cultivation details

A fairly common weed in Britain, it succeeds in most soils in sun or light shade and avoids acid soils in the wild. It prefers a damp rich soil[238]. This is the plant that Socrates is said to have used to kill himself, though this is probably an error[207]. It requires a large dose if it is to be lethal (this contradicts with the notes above on toxicity[K]), and death from this plant can be very painful whilst Socrates is said to have died without pain[207]. Another report says that poisonous doses cause paralysis, which starts at the feet and moves up the body. There is no pain, the mind remains clear and lucid until death, which is caused by asphyxia when paralysis reaches the chest[232]. The whole plant has a foetid smell[7].

References   Carbon Farming Information and Carbon Sequestration Information

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Plant Propagation

Seed - best sown in situ as soon as it is ripe in the late summer. It usually germinates in the autumn.

Other Names

If available other names are mentioned here

beaver poison; carrot-fern; fool's-parsley; hemlock; herb bennet; kecksies; kex; musquash root; poison parsley; spotted corobane; spotted-hemlock; spotted-parsley. Spanish: encaje cimarrón; panalillo; perejil de chucho; perejil de monte; zanahoria silvestre. French: cigue maculee; cigue tache; cigue tachetee; grande ciguë Chinese: du shen. Brazil: cicuta; funcho-selvagem. Germany: Gefleckter Schierling. Guatemala: perejil de chucho; perejil de monte. Italy: cicuta maggiore. Netherlands: gevlekte scheerling. Sweden: odört.

Native in temperate regions of Europe, West Asia, and North Africa. Introduced and naturalised in Asia, North America, Australia, and New Zealand.

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

This plant can be weedy or invasive. Considered an invasive species in 12 U.S. states. Competes with pasture and crops and encroaches on native vegetation, while posing a serious health hazard to virtually all livestock, and humans.

Conservation Status

IUCN Red List of Threatened Plants Status : This taxon has not yet been assessed.

Related Plants
Latin NameCommon NameHabitHeightHardinessGrowthSoilShadeMoistureEdibleMedicinalOther

Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.


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Botanical References


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Readers comment

Chris Smith   Wed Jul 26 18:52:30 2000

I am looking for a source of this plant near to where I live. Does anyone have any sightings they can pass onto me? I live in Dronfield a town outside of Sheffield.

Inna Mazanov   Tue Aug 10 13:22:37 2004

In Russia this plant use for treat all kinds of cancer and it is works. Is anybody herd about this?

M.Shahid   Tue Nov 8 2005

In Homeopathy this plant is being used to treat many symptoms,physical and mental emotional. And it is a very deep acting remedy,which is being used to treat cancer,depression,anxities M.shahid

M.Shahid   Wed Nov 9 2005

I would like to add a link here,for the readers who want to know more about conium,s use in homeopathy.


Dr. med. Veronika Rampold   Mon Dec 26 2005

In Germany there are some kinds of umbellifers which look very similar to the Hemlock but seem to be harmless. I saw real Hemlock only once before, in Bavaria, at the side of a river on an elevated dry place. The criterion to differentiate the real Hemlock from its harmless siblings is that Hemlock smells "like mice" and has brownishred "rusty" spots on its stalks. I would never, even in famine, consume Hemlock as a potherb. I ask meself whether the authors who mention that, have been clear in mind or not when they wrote it down.

Muhammad Shahid   Mon Feb 11 2008

Conium maculatum has been introduced and naturalised in many other areas, including much of Asia, North America and Australia. Poison hemlock is often found on poorly drained soils, particularly near streams, ditches, and other surface water. A useful trick to determine whether a plant is poison hemlock rather than fennel, which it resembles, is to crush some leaves and smell the result. Fennel smells like anise or liquorice, whereas the smell of poison hemlock is often described as mouse-like or musty.[citation needed] Considering the high toxicity of poison hemlock, if the plant cannot be identified it must be discarded.

Dr. Hitesh Patel   Thu Jan 15 2009

Can any body give me its name in Gujarati and Hindi language

   Dec 18 2015 12:00AM

It was effective. Very effective.

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