Herself's Houseplants

A new species of carnivorous pitcher plant has been found by Fauna & Flora International (FFI) in Cambodia’s remote Cardamom Mountains.

The discovery of Nepenthes holdenii is an indicator of both the stunning diversity and lack of research in the forests of the Cardamom Mountains.

The large red and green pitchers that characterize Nepenthes holdenii are actually modified leaves designed to capture and digest insects. The pitchers can reach up to 30 cm long. The carnivorous strategy allows the plants to gain additional nutrients and flourish in otherwise impoverished soils.

A further unusual adaptation seen in this new species is its ability to cope with fire and extended periods of drought. Cambodia’s dry season causes forests to desiccate and forest fires are common.

Nepenthes holdenii exploits the clearings caused by these regular blazes by producing a large underground tuber which sends up a new pitcher-bearing vine after the fires have passed.

British photographer Jeremy Holden, who first found the plant on the FFI survey and after whom it is named, said: ‘The Cardamom Mountains are a treasure chest of new species, but it was a surprise to find something as exciting and charismatic as an unknown pitcher plant’.

This discovery is the latest in a series of new species described from the Cardamom Mountains, including a green-blooded frog and a number of new reptiles.

Jenny Daltry, FFI Senior Conservation Biologist said: ‘The flora of Cambodia is still poorly known and potentially holds many new species for researchers to discover’.
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The Venus flytrap has a “memory”. In order to avoid reacting to a “false alarm”, the plant does not snap shut at the first touch of the sensory hairs. Instead, there must be at least two stimulations of the hairs within 30 seconds. After that, the trap closes fast so that the prey cannot make a last-gasp escape. How does the trap’s memory work? The hypothesis is that certain messenger chemicals are released every time the hairs are stimulated, and these substances accumulate in the trap. Only when these substances reach a certain threshold concentration does an ion channel open – like the mechanism used to transmit signals in our nerve cells—producing an action potential that allows the leaves of the trap to shut.

The trap snaps shut

Trap closing chemical factors

Researchers isolate the substance that causes Venus Flytraps to close