Angiopteris weimingii (Marattiaceae): a new endangered fern species from southern Yunnan, China, revealed by morphology and phylogeny

Angiopteris weimingii, a morphologically distinct new species of Angiopteris (Marattiaceae) from southern Yunnan, China, is described. Compared with A. itoi, the new species can be distinguished by a taller habit (1.2-2.5 m vs. 0.5-1.5 m), a greater number of pinnae pairs (8-13 pairs vs. 4-9 pairs), a caudate tip (1 cm vs. 2-4 cm), the position of sori from the leaf margin (2 mm vs. 3-5 mm), spore color (yellow vs. white), and spore ornamentation (densely verrucate vs. clavate-echinate). Molecular phylogenetic analyses confirm its affinity with the Archangiopteris clade. With a single known population of approximately 30 adults and severe habitat destruction, the species is assessed as Critically Endangered (CR) under IUCN criteria.