Trop picks: Sarracenia purpurea

In a few weeks, I shall be traveling across the planet to hunt for pitcher plants in the rainforests of Sumatra.

But, I'd like to point out that carnivorous plants are not exotic denizens of far-away tropical jungles. Pitcher plants like Sarracenia purpurea (more imaginatively called devil's boot) can be found in the temperate zone too. Although increasingly endangered, they populate forests throughout the colder parts of the North American continent.

Like its tropical cousins, S. purpurea lives in a nutrient-poor environment, so the ability to trap and digest animals (primarily ants in this case) is indispensable to its survival.

The pitcher itself is a teeming swamp. Its water-filled cavity is a host not just to the plant's prey, but to a series of other creatures that feast on that prey, including lake flies, microscopic aquatic invertebrates known as rotifera, mites, numerous species of bacteria and protozoa (that's single-celled organisms if you've forgotten your high school biology), and last but not least, a species of mosquito, Wyeomyia smithii, that is unique to this micro ecosystem.

European explorers knew of S. purpurea as early as the sixteenth century, and the indigenous tribes of the Great Lakes have known of it even longer, exploiting its unique properties for medicinal purposes.

Oddly enough, amateur gardeners have long struggled with the idea that S. purpurea requires cold just as much as it does warmth to flourish. Perhaps we get too caught up in the distinction between tropical and temperate.

Thankfully, our ideas about nature have evolved (hint: it's not something that happens only in hot places). Indeed, we're even beginning to recognize biodiversity hotspots in the cold North.