Pteris austrotaiwanensis Y.S. Chao

Yang, Dongmei, Wang, Jiamei, Guo, Rui, Zhu, Hongjuan, Ma, Changwang, Yu, Jing, Liu, Ya, Wu, Yougen & Shang, Hui, 2024, New taxonomic treatments in the Pteris fauriei group (Pteridaceae), Phytotaxa 647 (3), pp. 223-236 : 233

Pteris austrotaiwanensis Y.S. Chao in Taiwania 66(3): 313, f. 1A–C. 2021.

Type:— CHINA. Taiwan: Kaohsiung, Mt. Meilun , Y.S. Chao 3255 (holotype TAIF!, isotype TAIF!)

Pteris fauriei Hieron. var. chinensis Ching et S.H. Wu in Acta Bot. Austro Sin. 1: 10. 1983.

Type:— CHINA. Guangdong: Qujiang, C. Wang 31659 (holotype IBSC!, isotype PE!)

Description:—Rhizomes short-creeping, densely covered with linear-lanceolate black-brown scales. Fronds clustered, 50–80 cm long, nearly monomorphic; stipes 20–40 cm long, stramineous or abaxially red, sparsely scaly at base; laminae green to dark green, herbaceous, ovate, 15–44 cm long, 15–30 cm wide, bipinnatisect; lateral pinnae lanceolate, 3–6 pairs, 16–22 × 1.8–6 cm, opposite, sessile, with one pair of basiscopic pinnules, apex caudate, 2–3 cm long; segments falcate, 20–35 × 3–8 mm, apex acute or obtuse, margins entire; veins forked, free. Sori linear; spore number 32, spore size 48.9 × 26.8 μm.

Distribution: —In dense forests, below 1000 m, South China, Guizhou and Taiwan.

Specimens examined: — CHINA. Guangdong: C. Wang 40734 (PE), Y.H. Yan, S.L. Jin, Y. Wang & X.F. Zhu WYD198 (CSH). Guangxi: R.H. Jiang, J.C. Yang & S.S. Mo 11493 (IBK), L.Y. Yu, B.Y. Huang, D.X. Nong et al. 451422121209016LY (GXM), J.M. Wang 20150129, 20150129-3 (IBSC). Hainan: W.T. Tsang 616 (PE), S.Y. Dong 499 (PE). Guizhou: H.J. Wei, J.B. Zhang & Y. Wang WYG047 (CSH).

Taxonomic notes: — Pteris austotaiwanensis is different from P. fauriei by broader lateral pinnae (up to 6 cm wide) and wider segments of pinnae (up to 8 mm wide). Its herbaceous laminae, ovate lamina shape, broad lateral pinnae, and wide segments are similar to P. latipinna , but the laminae of P. austrotaiwanensis are green to dark green, while those of P. latipinna are light green.

According to the study of Chao et al. (2022), the very similar P. austrotaiwanensis and P. latipinna have different chloroplast and nuclear DNA haplotypes but share similar habitat preferences and the same ploidy level. Therefore, their similarity in morphology is probably caused by adaption to this specific habitat.