Lily of the valley is a perennial, rhizomatous herbaceous plant belonging to the Asparagaceae family (previously included in the Liliaceae). It grows up to 20 cm tall and is native to the pre-Alpine regions of Italy. It is widespread in Europe, North America, and Asia. The name Convallaria comes from the Latin name Lilium convallium or "lily of the valleys."

It is cultivated as an ornamental plant in shady areas of parks and gardens to adorn flowerbeds and undergrowth, as well as for the industrial production of cut flowers or forced growth in greenhouses for the winter commercialization of potted flowering plants. The fragrance of lily of the valley is used in perfumery, although synthetic alternatives are often preferred. It is also used for its medicinal properties due to certain glycosides such as convallatoxin, convallamarin, convallarin, and convallaric acid.

While some non-medical sources claim it is highly poisonous, there are no published cases of death due to the use of this plant in humans, and "most exposures result in minimal or no toxicity." Extensive reviews of exposures to lily of the valley have found that few people show symptoms, and only a small minority (0.3%) develop severe but transient symptoms. This plant is toxic in all its parts except the rhizome, due to its content of cardioactive glycosides, including convallatoxin, which has a cardiac activity 10 times stronger than digitoxin. As a result, its use is not recommended without medical advice; it can have emetic (vomiting-stimulating), drastic purgative, and cardiotoxic effects. For topical use, an infusion is used for earwashes, while the dried and powdered rhizome has a sneezing effect.