Diplazium kappanense Hayata (1919: 143)

Pongkai, Puttamon, Zhang, Li-Bing, Boonkerd, Thaweesakdi & Pollawatn, Rossarin, 2023, Revision of the fern genus Diplazium (Polypodiales: Athyriaceae) in Thailand, Phytotaxa 631 (1), pp. 1-69 : 26-29

10. Diplazium kappanense Hayata (1919: 143) . Fig. 13 .

Type: Taiwan Island. Kappanzan , U. Faurie s.n. (? TI, not seen) .

Plants terrestrial, Stems ascending, 2.0– 2.5 cm diameter, covered with scales at apex; scales 7–10 × 0.5–0.6 mm, linear with long tail apex, dark brown to nearly black, margin thick and toothed. Fronds up to 1.10 m, bipinnate; petioles 40–50 cm, 5–6 cm diameter, deep green, densely scaly and dark at lower part. Laminae 50–60 × 40–50 cm, bipinnate, subdeltoid to ovate-deltoid in outline, suddenly narrowing upwards, glabrous, papyraceous, light green; pinnae 8–10 pairs, alternate, 25–30 × 15–20 cm, oblong in outline, apex gradually narrowing towards forming long acuminate apex, stalked; stalks 3–4 cm; pinnule 10–12 pairs, alternate, 8–10 × 1.5–2.0 cm, oblong, apex long acuminate, base obtuse to subtruncate; margin lobed; lobes 1/3 way to costule, apex round, margin dentate; stalked; stalks 2–3 cm; veins pinnate, 5–6 pairs, veinlets free, forked. Sori 2–4 mm, elongate along veinlets, oblong, halfway between midrib and margin of lobe, indusiate; indusial linear, thin, persistence. Spores monolete, 32.5–35 × 17.5–22.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds.

Thailand: —NORTH-EASTERN: Loei (Phu Kradueng); SOUTH-WESTERN: Prachuap Khiri Khan (Khao luang); CENTRAL: Nakhon Nayok (Khao Yai) Distribution: —China, Japan, Taiwan Island, and Veitnam. Ecology: —On moist ground along stream banks in light shade at about 800 m elev. Specimens Examined:—THAIALND. Nakhon Nayok, Khao Yai, D. J. Middleton et al. 3772 ( BKF); Loei, Phu Kradueng, P. Jadprajong 191 ( BCU); Prachub Kirikhan, P. Pongkai 160 ( BCU); ibis., P. Pongkai 161 ( BCU). JAPAN. Kyushu, M. Tagawa 8130 ( BM, PE); TAIWAN ISLAND. Tai Bei City, R. Knapp P 198 ( ATIF). Note: —According to the Flora of China, Diplazium taiwanense Tagawa is a synonym of D. kappanense .

Figures

FIGURE 13. Diplazium kappanense Hayata. A, pinna. B, a part of pinnule with sori. C, scale showing toothed and black marginal cells. P. Pongkai 160 (BCU).