A researcher is tramping the southern forests and northern pastures of Western Australia, to document the most varied collections of carnivorous plants in the world.

There are about 600 species of insect-eating plants recorded globally, and about one-third of those are found in WA.

PhD student Laura Skates has spent weeks travelling to some of the most remote parts of the state, documenting an array of brightly coloured species, and trying to understand their biology.

"I'm really interested in answering the question of how hungry are these carnivorous plants," she said.

PhD student Laura Skates has travelled to remote parts of WA to study carnivorous plants. ( Supplied: Laura Skates )

"I want to know how much they rely on the nutrients they get from prey they've captured, compared to how much they rely on nutrients they get from the soil."

While the Venus flytrap plant is well-known thanks to the musical Little Shop of Horrors — in which a plant goes rogue and starts eating people — carnivorous plants take many forms, and use a variety of methods to trap their prey.

Some use a 'snap trap', to capture insects in fast-shutting jaws, while 'flypaper traps' use sticky liquid to ensure flying bugs.

Laura Skates says people are often surprised at how striking the species are.

"Seeing carnivorous plants in the wild is always really beautiful ... the sticky-leaf plants I study have really shiny, dew-like drops on their leaves and it's quite beautiful to see them," she said.

"Often they're really nicely coloured as well, a mix of those green and red colours."

Many of WA's carnivorous plants are brightly coloured. ( Supplied: Laura Skates )

Black market threat

The dozens of species found in WA are relatively unstudied compared with those overseas, which botanists say leaves them vulnerable.

Ms Skates said one potential threat comes from collectors, who target rare species in a similar way to black market reptile collectors.

"Unfortunately a lot of carnivorous plants can come under threat from changes to habitat and even illegal collection, where people might want to take them home and keep them for themselves," she said.

"Illegal collection of carnivorous plants has been known to be an issue, and there can be a black market for them … but you can buy them legally, so people should find out about that from Carnivorous Plant Society."

The last word, she said, should go to naturist Charles Darwin, who wrote extensively about carnivorous plants in the 1870s.

"The first person to ever properly study carnivorous plants was Charles Darwin, and he thought they were the most wonderful plants in the world … so I can't argue with that," Ms Skates said.

"I think carnivorous plants are one of those plants that even people who don't like plants will think are pretty cool.

"They're just really beautiful plants, and they're really fascinating how they use this special mechanism to get nutrients that they can't get from the soil."