A tropical pitcher plant is a carnivorous plant that is native to Southeast Asia and Australia. Also known as a monkey cup, more than 90 species of tropical pitcher plants have been identified to date. Most species of this plant form vines that cling to trees or other plants for support. The monkey cup is part of the Nepenthaceae family and the Nepenthes genus.
The tropical pitcher plant grows in areas with nutrient-poor soil or on other plants. It is considered an epiphyte instead of a parasite when it grows on another plant because it does not take nutrients from its host. The tropical pitcher plant has adapted to the lack of nutrients in its environment by becoming carnivorous to supplement its diet.
As they mature, the leaves of the tropical pitcher plant form a pitcher-like structure. The leaf starts off looking like a regular leaf, then forms the pitcher at the top. While the leaf is immature, a top covers the trap. As it becomes larger, it fills with air, the top lifts, and water is captured inside.
Insects are attracted to the red colors of the pitcher and the scent of the nectar. After the insect crawls inside of the tropical pitcher plant's trap, it can't escape. As it tries to climb the interior walls of the pitcher, the waxy surface peels off, and the insect slides back down into the trapped liquid. This struggle triggers the tropical pitcher plant's digestive glands to release a strong acid that will quickly digest the insect. Most of these plants consume primarily insects, but some tropical pitcher plants are large enough to digest small mice.
Other insects live in a symbiotic relationship with the tropical pitcher plant. Small foraging insects such as ants live in the shade of the pitcher plant and collect the remains of other fallen insects. The foraging insects are provided with shelter and food, and they prevent the pitcher plant from being surrounded by an overabundance of decaying matter that could harm the plant.
When grown as a houseplant, the tropical pitcher plant does well under the right conditions. It thrives under bright but indirect light. The soil should never be allowed to become completely dry and should be flooded occasionally to remove accumulated salt. This plant will live in a low-humidity environment but will stop producing pitchers until it receives moist air. A well-drained planting medium, such as sphagnum moss, peat moss or perlite, should be used.