Argemone is a wild flowering plant belonging to the poppy family, commonly seen growing along roadsides, in fallow fields and wastelands across many parts of India. It is easy to recognise by its prickly, spiny leaves and stems and its bright yellow sap, and it produces small black seeds that closely resemble mustard seeds in size and colour.
Because the plant grows as a weed among mustard crops, its seeds sometimes get mixed in accidentally at harvest and end up pressed along with the mustard, contaminating the resulting oil. This resemblance in seed appearance is the root cause of most of Argemone's harmful effects on people.
Harmful effect 1 - Internal poisoning: The seeds and oil of Argemone contain toxic alkaloids. When this oil is consumed unknowingly, mixed into cooking oil, it can cause vomiting, severe swelling of the limbs, and in serious cases lasting damage to organs such as the liver.
Harmful effect 2 - Eye and skin irritation: Direct contact with the plant's yellow sap can irritate the skin and cause redness or rashes, and if the sap gets into the eyes it can lead to painful inflammation of the eye's surface.
Therefore, Argemone is a wild poppy-family plant whose seeds contaminate mustard oil and whose sap and seeds are toxic, causing internal poisoning with organ damage as well as skin and eye irritation on contact.