Polystichum subobliquum Tagawa (1935: 138)

Wan, Xia, Knapp, Ralf, Chen, De-Kui, He, Hai & Zhang, Li-Bing, 2023, Taxonomic notes on some East Asian pteridophytes, Phytotaxa 597 (2), pp. 128-140 : 132

Polystichum subobliquum Tagawa (1935: 138) . Figure 6 .

Type:— Taiwan Island: Taito (Taitung): between Kiriyama et Tippon-zan, about 2000 m, 4 Oct. 1934, M . Tagawa 1092 ( KYO) .

Polystichum subobliquum is often treated as a synonym of P. obliquum (D. Don 1825: 3) T. Moore (1858: 87) (e.g., Knapp 2011, Zhang & Barrington 2013, Hsu et al. 2019). However, P. subobliquum (Knapp 3625, 4178, P!) has lower pinnae that are not reflexed and sori close to pinna margins, but P. obliquum has lower pinnae often reflexed and sori closer to the midrib. Therefore, here we reinstate this species. It is endemic to Taiwan. Our unpublished molecular data supports the separation of the two species.

Figures

FIGURE 6. Polystichum subobliquum.—A. Habitat & habit.—B. Lower portions of petioles showing scales.—C.Adaxial view of middle portion of lamina.—D, E. Abaxial views of portions of laminae (photo credit: Ralf Knapp).