A black devil flower that steals its food from fungi turned up in a Thai national park

Botanists working in western Thailand have described a flowering plant so strange that they named it after a demon. The species, found growing beneath leaf litter in a national park, has no green tissue, makes no food of its own, and spends nearly its entire life hidden underground. Its discovery adds a single, fragile population to one of the most obscure plant genera on Earth, and it arrives with a warning attached: the population is so small that the species could disappear before most people ever hear its name.

A plant that gave up photosynthesis

The new species belongs to Thismia, a genus of small, leafless plants sometimes called fairy lanterns for their translucent, lantern-shaped flowers. Thismia plants contain no chlorophyll and cannot photosynthesize. Instead they are mycoheterotrophic, meaning they draw carbon and nutrients from underground fungal networks that are themselves usually connected to the roots of trees overhead, effectively parasitizing a partnership that ordinarily runs between fungi and taller plants.

That lifestyle keeps most Thismia species out of sight for almost their entire existence. Botanists from Chulalongkorn University and Prince of Songkla University found this particular population only when its flowers pushed briefly above the forest floor, a window that for many Thismia species lasts just days before the plant retreats back underground to complete its life cycle out of view. Because the plants have no leaves and no stem to speak of above ground, there is no season in which a botanist can simply walk a trail and expect to spot one; the flower is essentially the only visible evidence the species exists at all.

The tradeoff explains why the genus is so poorly documented worldwide despite having been known to science for close to two centuries. Without green tissue there is nothing to search for outside a narrow flowering period, and because each species tends to depend on a specific fungal partner and a specific patch of forest chemistry, populations rarely spread far from the spot where they first take hold.

Found at nearly 1,000 meters in Thong Pha Phum National Park

The species was collected in Thong Pha Phum National Park in western Thailand, growing at an elevation of close to 1,000 meters, according to the researchers who described it. That altitude and the seasonally dry conditions there are unusual for the genus, which more typically favors low-elevation, consistently damp forest floors, adding a habitat type to what is known about where Thismia can survive.

Researchers named the plant Thismia daemona, the devil flower, for its appearance rather than any behavior. The formal description was published in the open-access journal PhytoKeys, bringing the number of Thismia species recorded in Thailand to 16. Field botanists involved in the work have said the unusual elevation is itself a reason to keep surveying similar mid-altitude forest in the region, since a habitat that was not expected to support the genus may be hiding other undescribed populations.

Black petals and a demon-like face

The flower’s tepals are mostly black, arranged around a dome-shaped structure researchers describe as a mitre, with horn-like projections rising from its crown. Patches of vivid reddish-orange sit near its base, an arrangement that from certain angles resembles a pair of glowing eyes set into a dark face. The combination is what earned the plant its name and has drawn attention from botanists well outside Thailand since the description was published.

Even among Thismia species, which are frequently described in botanical literature using words like bizarre and alien, the coloring stands out. Most fairy lanterns documented in Southeast Asia run toward translucent whites, pale yellows, or reddish browns; a flower that is almost entirely black is rare enough that researchers flagged the coloration as one of the species’ defining features in the formal description, alongside its floral structure and elevation range.

Fewer than 50 known individuals

The entire known population of Thismia daemona consists of fewer than 50 individuals, confined to a single site smaller than a football pitch inside the park. Researchers have provisionally assessed the species as Critically Endangered, a status driven partly by that tiny population size and partly by where it grows: within a national park that draws tourists, where foot traffic, trail maintenance, or small shifts in soil moisture and fungal partners could eliminate the population before it is ever documented again.

Because Thismia depends entirely on a specific underground fungal partner, protecting a single visible flower is not enough. Researchers have noted that safeguarding the species means safeguarding the fungal network and forest conditions it relies on, something that is much harder to monitor than counting stems above ground. A logging road, a shift in the canopy overhead, or a change to the specific fungal community in the soil could wipe out the only known population without a single visible flower ever being disturbed directly.

Extending the known range of a rare plant lineage

Thismia daemona belongs to a section of the genus called Geomitra, previously known only from Peninsular Malaysia, Borneo, and Sumatra. Its presence in western Thailand pushes the documented range of that entire section northward for the first time, suggesting related species may be growing undetected in forests across mainland Southeast Asia. Because these plants surface so briefly and offer so little visual signal the rest of the year, botanists say targeted surveys during narrow flowering windows are likely the only realistic way to find them.

The finding fits a broader pattern in Thismia research: nearly all new species in the genus have turned up through chance encounters by researchers already surveying a forest for other reasons, rather than through searches aimed specifically at the genus. That pattern has led some botanists to argue that formal protected status for individual Thismia sites, rather than broader habitat protections alone, may be the most realistic way to keep newly found populations like this one from vanishing before they are fully studied.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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