Monkshood – Aconitum delphiniifolium

Alaska Wildflowers | Purple

Purple flowers of larkspurleaf monkshood taken in the interior of Alaska


Aconitum delphiniifolium

Common Names

larkspurleaf monkshood
mountain monkshood


A. delphiniifolium ssp. chamissonianum
A. delphiniifolium ssp. paradoxum
A. nivatum
A. delphiniifolium ssp. delphiniifolium
A. delphiniifolium var. albiflorum



Genus: Aconitum
Family: Ranunculaceae
Order: Ranunculales
Full Classification

Duration – Growth Habit

Perennial – Forb/herb

Table of Contents

Identification and Information
Uses – toxicology, poison, mythology
Distribution and Habitat
References and Further Reading

Identification and Information

A. delphiniifolium is a perennial herb growing from tuberous roots. The tuber is typically composed of a parent tuber and a single, continuous daughter tuber, connected by a short branch. The plant grows erect, 0.3-1 m (1-3 ft) high from a narrow stem. Taller plants require other companion plants to remain upright. The leaves are alternate, cauline, 7-13 cm (3-5 in) in width, and have five deeply divided lobes, each containing three smaller lobes.

The flowers are purple or dark blue, bilaterally symmetric, and distributed on raceme or panicle inflorescence of 3-15 flowers near the top of the stem. The blossoms are green or green-yellow before developing the purple color. The flower is slightly tubular, composed of 5 outer sepals and two petals that are hidden in the upper sepal hood. The lower two sepals are flat and slightly pointed at the tip, the 2 lateral sepals are kidney-shaped, forming the tube, and the upper sepal is the beaked crescent-shaped hood. The entire flower is 2-4 cm tall from the bottom of the pendant sepals to the top of the hood.

Monkshood looks similar to Larkspur, except with a narrower stem and a “hood” over the top of the purple to dark-blue flower.

Uses – Toxicology, Poison, Mythology

For information only (typically historical) – I take no responsibility for adverse effects from the use of any plant.

The whole plant is highly toxic to people and animals, as are all species in the genus aconitum. May even cause paraesthesia from skin contact, although not common.

Toxin – Aconitine poisoning

Plants of the genus Aconitum L. contain the alkaloid toxins aconitine, mesaconitine, hypaconitine, and others. The primary toxin is aconitine. Another similar species of, A. napellus was also known as “wolfsbane” because it was used as a nerve poison to kill wolves (typically put in raw meat as bait). It has documented use as a poison by the Inupiat. Many species of Aconitum L. have been used as arrow poisons. Ingestion of aconitine causes nerve paralysis, low blood pressure, ventricular arrhythmia, and heart failure. While the entire plant is poisonous, the roots have the highest concentration of the toxin.

The compound aconitine blocks the sodium-ion channels which help govern the voltage of muscles, myocardium, and neurons, leading to heart dysrhythmia that can lead to death. It binds to the receptors that govern the sodium channel, keeping them always open or in the “on” state.

Other symptoms of aconitine poisoning include strong contractions of the ileum of the lower intestines due to the release of acetylcholine from the postganglionic cholinergic nerves, leading to intense abdominal discomfort and pain as well as nausea, vomiting, and diarrhea. Neurological symptoms include numbness of the face and limbs and muscle weakness. It may also cause hypotension and a slow heart rate by activation of the ventromedial nucleus of the hypothalamus. Death is most often from refractory ventricular arrhythmia, or “electrical storm” in the heart and flatline.


It’s worth mentioning that there are claims of therapeutic effects of monkshood, especially in traditional Chinese medicine. It has been used historically to treat pain and fever. In the 19th and early 20th centuries, aconitine was even available in pharmacies. Typically the roots would be processed by soaking and boiling to reduce the alkaloid content. Due to it being difficult to process and get the dosage correct, the use of monkshood as a medicine frequently leads to accidental poisoning. We have many other fever reducers and painkillers today; I’d highly suggest using one with less chance of killing you. There are lots of stories of accidental poisonings, usually from drinking tea made from the plant (examples: Poison Control, Forbes, more reading below).

Poison & Mythology

The plant is infamous for being used as an intentional poison for both animals and people. It has frequently been hidden in food or drink to poison victims. In the past, it was difficult to detect poisoning by aconitine, similar to arsenic. Although it is easy to test for today, don’t get any wild ideas (there have been multiple convictions of people who killed or attempted to kill others by aconitum. In addition to the name wolfsbane, it has earned some other gruesome nicknames such as dogsbane, women’s bane, and wifesbane. It has been used to poison tip arrows and darts and even used as an experimental poison with hollow-tipped bullets by the Nazis during WWII. The more you look, the darker its history becomes.

In Greek mythology, aconitum grew out of the ground from the slobber of the three-headed dog that guarded the gates of Hell, Cerberus. In one of the more famous versions of the story, Cerberus was captured by Heracles, forcing it to leave the Underworld. When he reached the light of day, Cerberus vomited toxic bile, from which grew the plant wolfsbane.

During the Middle Ages, it was believed to repel not only wolves but werewolves as well. It was even used to “treat” lycanthropy, or werewolfism, often leading to the death of the patient.

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Distribution and Habitat

Aconitum delphiniifolium is native to Alaska, northwestern Canada, and eastern Siberia. It typically flowers June-September. Preferring richer soils, it is often found in subalpine areas in Alaska, in woods, rocky slopes, alpine tundra, meadows, or along stream beds.

In coastal areas of Alaska and the Aleutian chain, monkshood is often taller with larger flowers. This was once listed as a subspecies, A. delphiniifolium ssp. chamissonianum, but is now accepted as the same species.


RankScientific Name (Common Name)
KingdomPlantae  (plantes, Planta, Vegetal, plants)
   SubkingdomViridiplantae  (green plants)
      InfrakingdomStreptophyta  (land plants)
            DivisionTracheophyta  (vascular plants, tracheophytes)
               SubdivisionSpermatophytina  (spermatophytes, seed plants, phanérogames)
                           FamilyRanunculaceae  (buttercups, boutons d’or, crowfoot)
                              GenusAconitum L. (monkshood, aconite, wolfsbane)
                                 SpeciesAconitum delphiniifolium DC.

References and Further Reading


Field Guide to Alaskan Wildflowers, Pratt, Verna E. pg 7

Classification and Taxonomy

A. delphiniifolium  DC., ITIS Database

A. delphiniifolium DC. larkspurleaf monkshood, USDA Database

Uses and Toxicity

Wolfsbane: fictitious plant contains very real dangers, – Plant Profiles in Chemical Ecology

Monsters, Magic, and Monkshood, Chicago Botanical Garden

The Queen Of Poisons Strikes In San Francisco, Sam Lemonick – Forbes

The Queen of Poisons, dblum – Science Blogs (2010)

A. delphiniifolium DC., Native American Ethnobotany Database

Aconite Poisoning, Encyclopaedia Romana – Essays on the History and Culture of Rome

Aconite poisoning,

ACONITINE: A poisoner’s potion of choice, Paul May – University of Bristol

A. napellus (Monkshood): A Purple Poison, National Capital Poison Center –

Map and Distribution

Aconitum delphiniifolium, Larkspurleaf Monkshood, NatureServe Explorer

A. delphinifolium DC., GBIF

Description and Information

A. delphinifolium – DC., Plants For A Future

Larkspurleaf monkshood, Wildflowers of the National Forests in Alaska, USDA and US Forest Service

2. A. delphiniifolium de Candolle, Syst. Nat. 1: 380. 1817., Flora of North America


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