Poisonous Plants, Fungi, and Algae Poisonous Plants

A few Poisonous Plants

Dumb cane – calcium oxalate crystals

Yew (Taxus spp) - taxines

Pokeweed

Poke - Phytolacca americana Roots and seeds especially toxic Young stems and leaves often eaten as cooked greens - should be avoided? Toxic compound - phytolaccigenin - triterpene saponins Also contains toxic alkaloids and other glycosides

Oleander - Nerium oleander contains cardiac glycosides - oleandroside and nerioside

Castor bean - Riccinus communis

Ricin One of the most potent natural toxins known One seed can kill a child Inhibit protein synthesis by specifically and irreversibly inactivating eukaryotic ribosomes A single ricin molecule that enters the cytosol can inactivate over 1,500 ribosomes per minute and kill the cell Lots of possible medical applications - could also be used in biological warfare - weapon of mass destruction

Cycads Cycads are gymnosperms with a palm-like appearance They are found in tropical and subtropical areas of the world Large female cones with large seeds

Cycad toxins Cycasin and BMAA (beta-methylamino- alanine) Cycasin is a carcinogenic and neurotoxic glycoside BMAA is an unusual amino acid which is also neurotoxic and believed to act by mimicking glutamate and blocking glutamate receptors in the brain