The flowery trap

In this section, Saevus brings to you short stories of life from the undergrowth. These organisms often escape our attention but they can be of immense importance in the natural world.

When one thinks of carnivorous plants, the elegant vase of the pitcher plant immediately pops up in your head. A more knowledgeable person might venture to think about the Venus flytrap or the sundew plants. But the trivial bladderwort plants have very few takers.

Over 200 species of terrestrial and aquatic bladderworts are found on all continents, except Antarctica. All the species are included in just one genus, Utricularia. While most of the plant structure lies underground, only the flowering stem rises vertically from the ground. The name ‘bladderwort’ refers to the bladder-like traps located on the stolons (branching stem-like structures). The traps are recognised as one of the most sophisticated structures in the plant kingdom.

The traps are triggered by the hairs attached to them. When a prey brushes against these hairs, the trapdoor opens, sucking the prey and surrounding water and closing once the bladder is full. This entire incident takes place within ten to fifteen thousandth of second! These bladders vary greatly in size, allowing different species to hunt on a diverse array of prey, ranging from minute protozoa to fish fry and tadpoles. Utricularia are cultivated for their flowers, which are even compared to orchids by carnivorous plant enthusiasts.

 

Utricularia purpurascens, or Purple bladderwort, is an endemic plant of the northern Western Ghats, and is incorrectly dubbed as a synonym of U. graminiflora in most literature.

 

Image Credit: Pranad Patil

This article was first published in the 2015 May issue of Saevus magazine