In case you haven’t noticed from my last blog post on the Venus flytrap, I really enjoy reading and understanding the mechanisms behind how carnivorous plants function. Carnivorous plants are defined as plants that obtain most of their nutrients and energy supply by trapping and consuming animals, mainly insects and arthropods. The pitcher plant is one that falls under this category and is found to be native to the region of South East Asia.
Their main mechanism of action is with the presence of their modified leaves which act as pitfall traps that are shaped like pitchers – deep cavity filled leaves that fill up with digestive fluids when catching prey. The plant uses its attractive deep red color to lure prey and more easily bring them close enough that they fall into the
The most species- rich families of pitcher plants are the Nepenthaceae and Sarraceniaceae families. Specifically, the Nepenthaceae family contains one genus known as Nepenthes which in itself contains over 100 species and various hybrids. Known as “old world” pitcher plants, these plants have reduced symmetrical pitchers with a waxy coating on the inner surface of the wall which is used to allow the animal to slip and fall into the deep hollow opening. Genus Sarracenia from the family Sarraceniaceae are mainly native to North America and comprise of 8-11 various species.
How do these plants feed?
The secret is in the juices stored inside the bottom of the pitcher plant. The plant lures unsuspecting insects into its mouth, using scents stored as sweet-smelling juices, where they will be unable to climb back up by getting trapped in the fluid. Eventually the victim will lose its energy and get eaten up by the plant with the help of the juice. The nectar contains chemicals that slowly digest and swallow the skin of its prey and therefore eventually completely dissolve it into the juice the prey once tried to drink. The video below shows a pitcher plant trapping a frog inside the bottom of its opening.
The presence of inwards and downward pointing hairs on the inside of the pitcher ensure that once an insect falls inside, it cannot climb back out. The mechanism of digestion used by the plants includes the help of a liquid contained in the pitcher known as phytotelmata which is the fluid that gradually drowns the insect and dissolves it. Once dissolved, the prey is ultimately converted into a solution of various amino acids, peptides and phosphates and urea by which the plant in turn uses to obtain nutrition.
Lastly, the location in which these plants thrive in are areas in which soil quality is low and the minerals are too acidic for most other plants to survive in. This allows these plants to reply on other factors different from photosynthesis for survival – luring and trapping constituents of their insect prey.