Purple Pitcher Plant

Sarracenia purpurea may appear to be a simple, primitive pitcher plant. But that is just because it is small---do not be deceived, for this is a very complicated and subtle plant. Furthermore, it is clearly the most successful of all the Sarracenia in that its range is vast compared to its congeners. Oh yes, this is a very slick little plant.

Sarracenia purpurea pitchers are small, up to 30 cm long. They are squat and have a large lip. The pitcher lid, unlike in erect pitcher plants, does not shield the pitcher opening. Instead, the lid is erect, with a pair of lateral ear-like wings on each side of the pitcher lip. Instead of being called a lid, it is usually called the hood. This hood is usually beautifully veined with treelike patterns, and is covered with stiff hairs pointing towards the pitcher opening.

Sarracenia pitchers usually persist for only a year at most, but the pitchers of Sarracenia purpurea survive in fine shape for two years unless they are damaged by fire or truly excessively cold conditions. This might be part of the secret for their success. The pitchers are filled with fluid which contains enzymes that, for at least a portion of their first year of life, are produced by the plant. (Despite what you might read elsewhere, S. purpurea produces digestive enzymes; not everyone keeps up on their reading!) Digestion in the pitcher is aided, especially during the second year, by the commensal organisms that live in the pitchers.

Oh, as for commensals, there are many interesting creatures that live in the pitcher fluid. The mosquito Wyeomyia smithii is the most famous, as its larvae that flick about in the waters of the pitcher fluid have shown a genetic shift in their life-cycle in order to accommodate global climate changes. The ravenously carnivorous larvae of the midge Metriocnemus knabi also live in the pitchers. These larvae do not molest the larvae of Wyeomyia smithii mosquitos, but they do attack non-native mosquito larvae!