Abacopteris yunguiensis

Abacopteris yunguiensis is a fern species in the family Thelypteridaceae, with the specific epithet yunguiensis indicating a geographic origin in the Yunnan-Guizhou (Yungui) Plateau region of southwestern China, an area of extraordinary biodiversity and one of the world's major centers of plant diversity. The Yungui Plateau is characterized by complex terrain, diverse climatic zones ranging from subtropical lowlands to cool montane areas, and a rich flora that includes numerous endemic species. Abacopteris yunguiensis likely inhabits the moist, shaded forest environments of this region, including subtropical evergreen broadleaf forest, mixed montane forest, and stream-margin vegetation where humidity remains consistently high. As a member of Thelypteridaceae, this fern produces fronds from a rhizome that creeps along the forest floor, with the blade divided into pinnate pinnae displaying the typical morphology of the genus: lance-shaped to oblong pinnae with lobed margins and clearly visible venation on the lower surface. Sori are arranged in rows on the undersurface of fertile pinnae, protected by kidney-shaped indusia. The stipe bears brown scales at the base, transitioning to scattered hairs along the rachis. China harbors an exceptionally diverse Thelypteridaceae flora, with many endemic species concentrated in the humid subtropical regions of the southwest, making the Yunnan-Guizhou area a particularly important center of thelypterid diversity. Abacopteris yunguiensis contributes to this regional pteridophyte richness, occupying understory niches in forest habitats that support a complex mosaic of fern species across elevational gradients.