A crop of delicate white periscopes, each just a few centimetres tall, peek above the leaf litter in a Malaysian rainforest. They may resemble mushrooms, but they are actually the flowers of a parasitic plant species that is totally new to science.

Fairy lanterns (Thismia) are mysterious plants that only briefly emerge from underground as tiny, intricate flowers. Lacking the chlorophyll that helps plants photosynthesise to generate energy, they instead steal nutrients from fungi. Many species have disappeared from human eyes shortly after being discovered, sometimes never being seen again and other times reappearing decades later.

In 2017, Mat Yunoh Siti-Munirah, a botanist at the Forest Research Institute Malaysia in Kepong, saw images of ghostly flowers shared on social media by a nature guide at Malaysia’s Royal Belum State Park. Suspecting the photos depicted an undescribed Thismia species, Siti-Munirah and her colleagues visited the park two years later to search for the fairy lanterns.

“Most species of Thismia can only be found during a certain time of the year,” says Siti-Munirah. “Being in the right time and in the right place is very important.”

But luck was on their side. Beneath a tree, the team found several of the fairy lanterns, which turned out to be a new Thismia species called Thismia belumensis.

Thismia belumensis is new to science

Siti Munirah Mat Yunoh (FRIM)

Fairy lanterns typically have radially symmetrical flowers, often with odd, antenna-like projections. But in T. belumensis, a ring of tissue in a flower’s centre expands upwards into a “hood” that opens sideways, looking a little like a snake’s agape mouth

Maxim Nuraliev, a botanist at Lomonosov Moscow State University in Russia, says the discovery is “extremely interesting”.

“The species has a floral shape very rare in Thismia, known only in a single other species,” he says, one that probably hasn’t been collected since 1927.

In this previously known species, the structure is made of two distinct lip-like sections, differing from the new species’ hood, says Siti-Munirah.

Martin Dančák, a botanist at Palacký University Olomouc in the Czech Republic, thinks the hood may be involved in pollination. Its inner surface is covered in inward-pointing hairs, helping insects enter the flower, but discouraging them from exiting.

“Basically, this is the mechanism which some carnivorous plants use for directing the movement of insects into their traps,” says Dančák. But T. belumensis isn’t carnivorous and has two holes below the hood that insects could use to escape, he adds.

Siti-Munirah and her colleagues already consider the fairy lantern critically endangered. They found fewer than 10 plants, and the species’ small range in the park makes it vulnerable to things like trampling from off-trail hikers.

Journal reference: PhytoKeys, DOI: 10.3897/phytokeys.172.59336