Diplazium donianum (Mett.) Tardieu (1932: 58)

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 : 19-21

6. Diplazium donianum (Mett.) Tardieu (1932: 58) . Fig. 9 .

Asplenium donianum Mettenius (1859: 177) .

Type : INDIA. Assam, W . Griffith s.n. (holotype K001089390 ) .

Plants terrestrial. Stems creeping, 3–5 mm diameter, covered with scales at apex; scales 4–6 × 1 mm, linear, dark brown, margin thick and toothed. Fronds 50–60 cm, imparipinnate; petioles 20–30 cm, 5–6 mm diameter, green when living, brown when dried, black at lower portion, grooved above. Laminae 30–40 × 20–30 cm, oblong in outline, terminal pinna distinct from lateral one, glabrous, subcoriaceous, green; lateral pinnae 1–3 pairs, alternate, 15–20 × 3.5–5.0 cm, oblong or narrowly-lanceolate, apex acuminate, base acute or obtuse, margin entire or subentire, stalted; stalks 6–10 mm; costa grooved with minute hairs on adaxial surface; veins free, veinlet simple or forked, extending to margin. Sori more than 1 cm, elongate along veins, longest on acroscopic side of veinlets, indusiate; indusia thin, persistance. Spores monolete, 55–72.5 × 35–50 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds.

Thailand: —NORTHERN: Chiang Mai (Doi Suthep), Nan (Khao Nok), Tak (Doi Musoe), Phitsanulok (Thung Salaeng Luang); NORTH-EASTERN: Loei (Phu Kradueng); EASTERN: Nakhon Ratchasima (Khao Yai); SOUTH-WESTERN: Kanchanaburi (Thong Pha Poom); CENTRAL: Nakhon Nayok (Khao Yai); SOUTH-EASTERN: Chanthaburi, Prachin Buri (Khao Yai), Trat (Koh Chang); PENINSULAR: Nakhon Si Thammarat ( Khao Luang , Khao Nan, Ron Phibun, Khiriwong), Satun.

Distribution: — Bhutan, India, Nepal, China, Taiwan Island, Japan, Myanmar, Vietnam, Malaysia and Singapore.

Ecology: —On mountain slopes in light shade or in dense evergreen forests, usually below 1,000 m elev.

Specimens Examined:— THAILAND. Satun, A.F. G. Kerr 14535 (BK); no locality, A.F. G. Kerr 9309 (BM); Kanchanaburi, Thong Pha Poom, A. Sathapattayanon 41(BCU); Loei, Phu Kradueng, E. Hennipman 3683 (L); Nakhon Si Thammarat, Khao Luang, E. Hennipman 3684 (L); ibis, E. Hennipman 3698 (L); Nakorn Ratchasima, Khao Yai, G. Murata, N. Fukuoka C. Phengklai T16254 (L); no locality, J.F. Maxwell 01–139 (L); Nakhon Nayok, Khao Yai, J.F. Maxwell 01–732 (L); Nakorn Ratchasima, Khao Yai, J.F. Maxwell 74–875 (BK, L); Prachinburi, Khao Yai, K. Iwatsuki & N. Fukuoka T7392 (L); Prachinburi, Khao Yai, K. Larsen, T. Smitinand & E. Warncke 313 (L); Phisanulok, Tung Salaeng Luang, M. Tagawa , K. Iwatsuki & N. Fukuoka T2039 (L); Nakhon Si Thammarat, Khao Luang, M. Tagawa , K. Iwatsuki & N. Fukuoka T4563 (L); ibis, M. Tagawa , K. Iwatsuki & N. Fukuoka T5269 (L); Nakhon Si Thammarat, Khao Luang, M. Tagawa , K. Iwatsuki, H. Koyama & A. Chintayungkun T14641 (L); Kanchanaburi, Thong Pha Poom, P. Pongkai 150 (BCU); ibis, P. Pongkai 152 (BCU), Chiang Mai, Doi Inthanon, P. Srisanga & P. Suksathan 3246 (QBG); Nakhon Nayok, Khao Yai, S. Chongko 9 (L); Nakhon Nayok, Khao Yai, S. Chongko 9 (BKF); no locality, Sangkachun 749 (K); no locality, T. Smitinand 5908 (K); Nan, Khao Nok, W. La–ongsri et al. 1993 (QBG). CHINA. Hong Kong, Alexander s.n (K); Guangdong, C.G. Matthew s.n. (K); no locality, D.E. Boufford & B. Bartholomew 24963 (BM); no locality, W.T. Tsang 22367 (BM). JAPAN. K. Iwatsuki 3023 (BM); M. Ogata 133 (BM); M. Tagawa 2733 (BM). SINGAPORE. T. Lobb 33 (K). TAIWAN ISLAND. T. Tanaka 367 (BM); VIETNAM. W.T. Tsang 29527 (K); MALAYSIA. Pahang, B. Molesworth–Allen 4170 (K).

Note: —This species is similar to Diplazium bantamense in the field, but can be separated from the latter by having creeping rhizome, lacking gemmae and having stalk more than 5 mm long.

Figures

FIGURE 9. Diplazium donianum (Mett.) Tardieu. A, whole plant. B, a part of pinna with sori. C, toothed and thick margin sc scale showing toothed and black marginal cells. A. Sathapattayanon 41 (BCU).