Polystichum pseudostenophyllum Tagawa (1934: 92)

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 pseudostenophyllum Tagawa (1934: 92) . Figure 4 .

Type:— Taiwan Island: Taityu : in monte Noko-goe, 1933, J . Ohwi 3228 ( KYO) .

Polystichum pseudostenophyllum is often treated as a synonym of P. stenophyllum ( Franchet 1887: 117) Christ (1905: 27) (e.g., Kung et al. 2001, Zhang & Barrington 2013) and rarely recognized ( Knapp 2011, Hsu et al. 2019). The two species are morphologically distinguishable with P. pseudostenophyllum having firm coriaceous laminae 7–10 times longer than wide, pinna margins with obvious and spreading teeth, sori mostly on one side of the midrib, and indusia ca. 1 mm in diam.; and P. stenophyllum having coriaceous laminae 12–15 times longer than wide, pinna margins indistinctly serrate, sori on both sides of the midrib, and indusia <0.5 mm in diam. ( Knapp 2011). In addition, P. pseudostenophyllum can have lobed pinnae and the pinnae are long aristate and with rounded auricles, while P. stenophyllum never has lobed pinnae and the pinnae are short aristate and with acute auricles.

Polystichum pseudostenophyllum is currently known to be endemic to Taiwan, but it might as well occur in Mainland China. Polystichum stenophyllum occurs in both Mainland China and Taiwan ( Knapp 2011, Hsu et al. 2019), the Himalaya ( Bhutan, India, N Myanmar, and Nepal), and Japan ( Zhang & Barrington 2013, Ebihara 2016).

Figures

FIGURE 4. Polystichum pseudostenophyllum.—A. Habitat & habit.—B. Lower portions of petioles showing scales.—C, D. Adaxial views of middle portions of laminae.—E, F. Abaxial views of portions of laminae (photo credit: Ralf Knapp).