Lehtivihannes

Lehtivihannes is a Finnish term for toxic compounds present in plant leaves. It denotes a category of plant secondary metabolites that serve as chemical defenses against herbivores and pathogens. The substances vary widely among species and can include alkaloids, cyanogenic glycosides, tannins, terpenoids, and other metabolites. Humans or animals may be affected if leaves are ingested in sufficient quantities, or if contaminated feed is consumed, with severity depending on dose and exposure route.

Examples of leaf toxins include nicotine in tobacco leaves; atropine and scopolamine in deadly nightshade and other Solanaceae; cyanogenic glycosides in some ornamental leaves such as cherry laurel; coniine in hemlock; and tannins common to many deciduous leaves. The specific toxins and their concentrations can differ with plant part, growth stage, and environmental conditions.

In addition to their role in plant defense, some leaf toxins have historical or ongoing relevance in pharmacology and toxicology, while others pose risks in agriculture and wildlife management. Proper plant identification and knowledge of local flora are important to prevent accidental poisoning, particularly for children, foragers, and livestock owners.

See also phytotoxins, plant secondary metabolites, plant defense mechanisms.