taxonID	type	description	language	source
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	materials_examined	Type: — Qushui Town, Jiangcheng Hani and Yi Autonomous County, Yunnan Province, China, tropical seasonal rainforest along stream, alt. 324 m, 10 May 2024, L. J. Jiang 240510 (Holotype: PYU JLJ- 09 - 1591!; Isotype: HITBC 0133890!).	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	diagnosis	Diagnosis: — Differs from related species by the combination of characters: mature individuals generally less than 120 cm tall (vs. up to 150 cm in Angiopteris itoi and A. sugongii); rhizome ascending (vs. erect in A. itoi); petioles minutely tuberculate (vs. smooth in congeners); fertile pinnules involute (boat-shaped with upturned margins, exposing partial sori abaxially; vs. flat in others); sori long linear, of intermediate length (2 – 8 mm; vs. 2 – 4 mm in A. sparsisora and A. caudatiformis; 10 – 20 mm in A. bipinnata and A. itoi); and leaf margins finely serrate (vs. coarsely dentate in A. bipinnata). The morphological comparison between A. involuta and the other three most similar species is provided in Table 4.	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	description	Description: — Plants terrestrial, 60 – 120 cm tall. Rhizome stout, ascending. Fronds clustered, once pinnate or bipinnate. Stipes 45 – 60 cm × 5 – 8 mm, terete, sparsely tuberculate, densely covered with brown filamentous hairs when young (caducous), Sparsely covered with black, narrowly lanceolate scales (ca. 0.5 – 1.2 × 0.1 cm), as the leaves age, the color of the Stipe scales gradually changes from black to brown. Lamina to 120 cm, 1 – 2 - pinnate; rachis wingless. Pinnae 5 – 6 pairs, narrowly lanceolate, 16 – 22 × 18 – 23 cm; bipinnate subtriangular, 45 – 55 × 18 – 23 cm, with 4 – 8 pairs of oblong pinnules 5 – 14 × 1.5 – 3 cm (apical ones slightly larger), base broadly cuneate, asymmetrical, with 2 – 4 mm petiolules, margins serrate; Veins sparse, simple or forked, false veins absent; texture herbaceous, adaxially green, abaxially pale green when dry. Fertile pinnules with margins strongly revolute toward adaxial surface (boat-shaped), partially exposing abaxial sori. Sori long linear, 2 – 8 mm, of 7 – 30 sporangial pairs, 2 – 3 mm from margin; paraphyses inconspicuous. Spores brown, trilete; exospores with densely tuberculate-spinose ornamentation. The spore mature from May to June.	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	materials_examined	Additional specimens examined (paratypes): — Qushui Town, Jiangcheng Hani and Yi Autonomous County Yunnan, CHINA, tropical seasonal rainforest along stream, alt. 350 m, 26 May 2025, L. J. Jiang 250526 (PYU!).	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	etymology	Etymology: — The epithet involuta refers to its involute fertile pinnules. The Chinese name is suggested as ‘ 卷叶 Kfiü ẍ (juan ye guan yin zuo lian) ’.	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	distribution	Distribution and habitat: — Endemic to southern Yunnan (Jiangcheng County) and grows in tropical seasonal rainforest understory along streams (270 – 350 m).	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	conservation	Conservation status: — Critically Endangered (CR B 2 ab (iii )). Only five wilds adult individuals and four ex situ specimens (XTBG nursery) are known. The type locality has been converted to rubber plantations, highlighting the urgent need for further field surveys in adjacent areas to assess potential remaining populations.	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
D351D733FFC9FFC3D8ECFAFEFA13FB10.taxon	discussion	Notes: Molecular data place Angiopteris involuta in a clade with the species of Archangiopteris (A. bipinnata, A. chingii, A. latipinna, and A. nodosipetiolata Ting Wang tris, H. F. Chen & Y. H. Yan (2024: 181 )), while A. itoi, A. sparsisora, and A. sugongii form a separate lineage (Wang et al. 2024) (Figure 2).	en	Jiang, Li-Ju, Zhao, Jing, Niu, Hong-Bin, Zhou, Xin-Mao, Wang, Jia-Guan, He, Zhao- Rong (2025): Angiopteris involuta (Marattiaceae), a new endangered fern species from southern Yunnan, China, based on morphology and molecular evidence. Phytotaxa 732 (1): 35-45, DOI: 10.11646/phytotaxa.732.1.3, URL: https://doi.org/10.11646/phytotaxa.732.1.3
