Not all trees are nice (Hulton Archive/Getty Images)

Thus far, Tree Week has been kind to our arboreal friends, focusing on their value and overall inimitable perfection. But hey, since we’re not living in a “Giving Tree” fantasy, where all trees are selfless providers to man, it’s OK to talk about their darker (shadier?) side, too.

In fact, the Brooklyn Botanic Society is reveling in it, with a “Wicked Plants” exhibit dedicated to trees, shrubs, herbs and cacti deemed “suspicious species.” According to NPR, the plants in the exhibit can make you sick, give you hallucinations or even kill you outright. Particularly deadly specimens are marked with skulls and crossbones.

Poison plants have long been intriguing (as evidenced by the fictional 12th century monk, Cadfael), but there seems to be a newfound interest in these all-poison gardens. The Duchess of Northumberland has helped fund the restoration of her estate through public tours of a “poison garden” (as well as her labyrinthine, five-room tree house). Author Amy Stewart has also just published “Wicked Plants: The Weed That Killed Lincoln’s Mother and Other Botanical Atrocities.” The book is a history of accidental death and homicide by horticulture, an exposé on common ornamentals and an account of well-known drugs-from-plants like tobacco and coca that have killed millions. Sounds like good summer reading perhaps best enjoyed indoors.

More:
Why does the stink plant stink?
How Tree Houses Work
10 Unexpected Garden Decorations

Tree Week:
The “Ghost Forest” of Trafalgar Square
The Tree Museum: Because in the Bronx, Trees Talk
The Eco-friendly Bagpipes of Tanzania
That’s Not a Tree, It’s a Power Plant!