What's Blooming the Week of September 18th? Pitcher Plants

Nepenthes (Nepenthaceae)
Asian Pitcher Plants (Pitcher Plant Family)
Origin: Old World Tropics

One of the most unique genera in cultivation here at Selby Gardens is the genus Nepenthes. A carnivorous liana found primarily in the islands of South East Asia, Nepenthes grow in nutrient-poor soil and have adapted over the years by adding an organ. The “pitcher,” which many people assume to be a flower, is actually an extension of the leaf’s midrib. At maturity, plants will have two morphologically different pitchers called “upper” and “lower.” These structures are filled with a fluid of the plant’s own making, which both attracts and helps to digest its prey. Small insects, such as ants, comprise much of the menu, but the recently-discovered Nepenthes attenboroughii has been observed eating rats.

The pitchers don’t just help the plant get the food it needs; in addition they become an entire ecosystem unto themselves. Swarms of mosquitoes spend their larval days in the pitcher fluids, as do frogs and their tadpoles, even a species of crab in Malaysia. These animals are referred to as nepenthephiles. It is suspected that the relationship between the nepenthephiles and their hosts is mutually beneficial. The pitcher plant provides food and shelter to the critters, and in turn the critters speed up the digestion of the less fortunate drowned critters, consuming them and then…well, you get the idea.

A question we are often asked is, if the pitchers aren’t the flowers, then what are? Do pitcher plants flower? You bet they do, and they are in bloom right now! Male and female flowers are borne on different plants, in long flower stalks emerging from the leaf axils. When the female flowers have been pollinated, they form capsules with dozens to hundreds of wind-dispersed seeds. Species of Nepenthes can be seen every day here at Selby Gardens in our Tropical Conservatory, and may be purchased in our Gardens Shop. 

Text by David Troxell