Hidden inside the petals of a butter daisy in northern Thailand, a scientist found a brand-new life form — a dark, yeast-like fungus no one had ever named before. It turned out that was just the beginning. Researchers from Chiang Mai University and Kasetsart University discovered 16 entirely new species of fungus living quietly inside garden flowers and wildflowers across the region, more than quintupling the number of these fungi known to exist in Thailand. Their study appears in the journal IMA Fungus.
The new arrivals all belong to Aureobasidium, a genus of dark, yeast-like organisms that are surprisingly common around the world. Its members live almost everywhere, from human skin to glacial ice. Several are already prized in industry for making useful enzymes, fighting plant disease and even breaking down plastic. Yet despite how familiar these fungi are, almost nothing was known about how many different kinds call Thailand's tropical flowers home.
During a 2024 survey, the team collected 54 fungal strains from 31 species of flowers, including bougainvillea, butter daisy and periwinkle. By combining DNA analysis across five gene regions with microscopy and growth trials, they sorted out 16 brand-new species, along with five that were already known to science — four of which had never been recorded in Thailand before.
"Fermentation" proved to be a misleading word in more ways than one. Many of the new species looked almost identical under a microscope, and the DNA markers scientists usually rely on could not tell them apart. "This highlighted the limitations of relying on morphology alone, as well as on commonly used molecular markers," explained professor Nakarin Suwannarach of Chiang Mai University. By layering genetic data with information about shape, body chemistry and growth temperature, the team could finally spot the differences between closely related species. Suwannarach called the result surprising, because such a well-known group of fungi still held this much hidden diversity in Thailand.
Most of the new species take their names from the flowers where they were found — Aureobasidium bougainvilleae, A. catharanthi and A. plumeriae, for instance — while others honor the northern Thai places where they were collected. Two species, A. saisamorniae and A. savitreeae, pay tribute to leading Thai mycologists professor Saisamorn Lumyong and professor Savitree Limtong. "We wanted the names to tell a story," Suwannarach said, "either about where these fungi came from or about the people who have helped advance mycological research in Thailand."
The work matters beyond naming. A handful of Aureobasidium species have been tied to opportunistic infections, so knowing exactly which species occur naturally gives scientists a baseline to spot any change in their behavior. "This study demonstrates that multilocus phylogenetic analysis is not simply a tool for naming new species," Suwannarach added. "It can reveal hidden fungal diversity and provide essential baseline information for understanding and monitoring fungal populations in the future." In the petals of an ordinary flower, it turns out, there's still a whole world waiting to be discovered.