RANUNCULACEAE
The Ranunculaceae or buttercup family comprises approximately 2000 species of temperate herbs and climbers. They have simple alternate leaves, rhizomatous roots and flowers with 3 or more pistils which develop into tiny fruits called achenes. Ranunculaceae flowers are unique because every floral parts (petal, sepal, pistil, stamen) are distinct from one another. Almost all members of Ranunculaceae are poisonous, they have long been cultivated as medicine, poison and ornamental plant.
The most poisonous Ranunculaceae belong to the monkshood genus Aconitum, all 250 species are potentially fatal to humans. The Aleut, Chinese and Nepalese use Aconitum spp. to prepare arrow poison, and to dispatch pest predators like wolf, hence the nickname 'wolf's bane'. All parts of Aconitum (especially the root) contain aconitine, a diterpene-alkaloid which disrupts nervous conduction of the heart and brain. This leads to tingling sensation, followed by numbness, diarrhoea, convulsion and death due to cardiac arrhythmia. The herbal tincture of Aconitum is used as a topical pain-killer, ingestion of it can be lethal. A closely related genus Delphinium (larkspur) contain similarly toxic alkaloid called delphinine. Many Aconitum and Delphinium species are cultivated as ornamental flowers, but human poisoning is rare.
Other highly poisonous Ranunculaceae like the genera hellebore (Helleborus) and bane barry (Actaea) elaborate cardiac glycosides of the bufadienolide skeleton. Cardiac glycoside disrupts the heart's rhythm, low doses increase the force of contraction, toxic doses cause arrhythmia and death. Note: The common name hellebore also refers to poisonous plants of the family Melanthiaceae, like Veratrum spp.
The canonical buttercup genus (Ranunculus) and the windflowers (Anemone spp.) are all poisonous due to a glycoside toxin called ranunculin. When the plant tissue is injured, ranunculin undergoes enzymatic degradation to release a volatile toxin called protoanemonin, which causes skin blistering (contact dermatitis) and damage to the liver. Ranunculus spp. are known to cause severe chemical burn to humans who applied its tincture to treat joint diseases. R. scleratus is even reputed to have been used by professional beggars to create nasty skin lesions so that they would generate more 'income'.
Buttercup is so named because people once thought that butter obtained its colour from the golden yellow wildflowers which cows consume. In reality, cattle avoid Ranunculus by instinct, ingestion of which can cause death!
The most poisonous Ranunculaceae belong to the monkshood genus Aconitum, all 250 species are potentially fatal to humans. The Aleut, Chinese and Nepalese use Aconitum spp. to prepare arrow poison, and to dispatch pest predators like wolf, hence the nickname 'wolf's bane'. All parts of Aconitum (especially the root) contain aconitine, a diterpene-alkaloid which disrupts nervous conduction of the heart and brain. This leads to tingling sensation, followed by numbness, diarrhoea, convulsion and death due to cardiac arrhythmia. The herbal tincture of Aconitum is used as a topical pain-killer, ingestion of it can be lethal. A closely related genus Delphinium (larkspur) contain similarly toxic alkaloid called delphinine. Many Aconitum and Delphinium species are cultivated as ornamental flowers, but human poisoning is rare.
Other highly poisonous Ranunculaceae like the genera hellebore (Helleborus) and bane barry (Actaea) elaborate cardiac glycosides of the bufadienolide skeleton. Cardiac glycoside disrupts the heart's rhythm, low doses increase the force of contraction, toxic doses cause arrhythmia and death. Note: The common name hellebore also refers to poisonous plants of the family Melanthiaceae, like Veratrum spp.
The canonical buttercup genus (Ranunculus) and the windflowers (Anemone spp.) are all poisonous due to a glycoside toxin called ranunculin. When the plant tissue is injured, ranunculin undergoes enzymatic degradation to release a volatile toxin called protoanemonin, which causes skin blistering (contact dermatitis) and damage to the liver. Ranunculus spp. are known to cause severe chemical burn to humans who applied its tincture to treat joint diseases. R. scleratus is even reputed to have been used by professional beggars to create nasty skin lesions so that they would generate more 'income'.
Buttercup is so named because people once thought that butter obtained its colour from the golden yellow wildflowers which cows consume. In reality, cattle avoid Ranunculus by instinct, ingestion of which can cause death!
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| Ranunculus cantoniensis, flower and foliage. |
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| Ranunculus cantoniensis, showing multiple pistils which will develop into achenes. All parts of R. cantoniensis contain ranunculin, which can cause contact dermatitis. |
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