While recent torrential rain has unsettled many Maui residents, scientists have announced the discovery of a tiny fern, endemic to the Valley Isle, that holds its ground in flash floods.

That’s because it has found its niche — and is not about to give it up — said botanist Ken Wood of the National Tropical Botanical Garden. Working with researchers from Haleakala National Park and the Plant Extinction Prevention Program of the University of Hawaii at Manoa, he found the new species, Athyrium haleakalae, alongside forest streams high on the slopes of Haleakala, for which it is named.

Animals and plants tend to fill in all the niches in a habitat, and Athyrium haleakalae adapted to the extreme conditions along the very edge of streams, Wood said by phone from Kauai. The fern also thrives under the ledges of waterfalls.

“It only occurs where there is very fast-moving water,” Wood said.

How does the delicate-looking plant hang on?

“Its very tenacious rhizomes (stalks) cling to the cracks inside the basalt walls,” and lying low is an advantage, Wood said, noting that larger fern species get uprooted by floods.

Because Athyrium haleakalae is unique to Maui and only 300 individuals have been found, all in native forests threatened by invasive species, it is critically endangered as defined by the International Union for the Conservation of Nature, said Wood, who coauthored a scientific paper on the fern with Warren Wagner of the Smithsonian Institution.

Due to habitat loss, “It’s only at higher remote elevations that you begin to see the magic of an intact Hawaiian ecosystem,” he added.