Any of a large class of organic, nitrogen-containing ring compounds that have a bitter taste, that are usually water-insoluble and alcohol-soluble, that form water-soluble salts, and usually exhibit pharmacological action, as nicotine, morphine, or quinine. 

• Aconite
• Allspice
• Black Snake Root
• Bloodroot
• Blue Cohosh
• Boxwood
• Celandine
• Common Poppy
• Crotalaria
• Crow Poison
• Death Camas
• Dicentra
• False Hellebore
• False Jessamine
• Fume Wort
• Hellebore
• Hemp
• Horse Nettle
• Indian Hemp
• Indian Poke
• Jimson Weed
• Larkspur
• Lobelia
• Lupines
• Marijuana
• Monkshood
• Moonseed
• Nightshade
• Pink Death Camas
• Poison Darnel
• Poison Hemlock
• Poison Rye Grass
• Rattle weed
• Rock Poppy
• Senecio
• Spider Lily
• Spotted Cowbane
• Spotted Water Hemlock
• Stagger Grass
• Stagger weed
• Sweet Shrub
• Thorn Apple
• Varebells
• Wild Parsnip
• Wolfs-Bane
• Yellow Jessamine