Diplazium subintegrum Holttum (1937: 125)

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 : 56

26. Diplazium subintegrum Holttum (1937: 125) . Fig. 32 .

Type: MALAYSIA. Pahang, Holttum, R.E. 31350 (holotype SING, isotype K000443923 !) .

Plants terrestrial. Stems erect, 5–6 cm diameter, densely scaly at apex; scales 12–15 × 2–3 mm, narrowly-lanceolate with long tail apex, brown, concolorous, margin entire with caducous membrane. Fronds 60–75 cm, pinnate; petioles 30–40 cm, 4–5 mm diameter, nearly black, glabrous, densely scaly at lower part. Laminae unipinnate 30–35 × 15–20 cm, outline oblong; terminal pinna distinct, about 10 × 4 cm, subdeltoid, apex acuminate, margin near base lobed; lateral pinnae 10–12 pairs, 10–15 × 2.0– 2.5 cm, narrowly oblong, apex acuminate, base round, margin subentire to crenate, dentate or serrate near apex, stalked; stalks 1.5–2.0 mm long; veins free, pinnate, veinlets 2 pairs. Sori 8–10 mm, elongate along veinlets, diplazoid, usually on acroscopic veinlets of vein group, indusiate; indusia linear, thin, pale brown, persistent. Spores monolete, 37.5–45.0 × 25.0–27.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds.

Thailand: —NORTHERN: Phitsanulok (Salaeng Haeng) ; CENTRAL: Nakhon Nayok (Khao Yai) ; SOUTH-EASTERN: Prachinburi (Khao Yai) , Chanthaburi (Khao Soi Dao) , Trat (Koh Chang) ; PENINSULAR: Nakhon Si Thammarat (Khao Luang, Khao Nan) , Yala .

Distribution: — Malaysia and Indonesia.

Ecology: —On rather dry ground near stream banks in light shade at 800–1,000 m. elev.

Specimens Examined:— THAILAND. Prachinburi, Khao Yai, C. Khunwasi 54 (BCU); Nakorn Nayok, Khao Yai, E. Hennipman 3998 (L); Nakorn Nayok, Khao Yai, J.F. Maxwell 01-535 (L); Nakorn Nayok, Khao Yai, K. Iwatsuki & N. Fukuoka T7379 (L); Nakorn Nayok, Khao Yai, K. Larsen, T. Smitinand & E. Warncke 163 (L); ibis., K. Larsen, T. Smitinand & E. Warncke 312 (L); no locality, M. Tagawa et al. T4790 (K); Nakhon Si Thammarat, Khao nan, P. Pongkai 35 (BCU); Nakhon Si Thammarat, Khao Luang, P. Pongkai 66 (BCU); Nakhon Si Thammarat, Khao Luang, P. Pongkai 67 (BCU) ibis., P. Pongkai 114 (BCU); ibis., P. Pongkai 115 (BCU); Nakorn Nayok, Khao Yai, S. Chongko 50 (L); Nakhon Si Thammarat, Khao Luang, T. Boonkerd 35 (BCU); Nakhon Si Thammarat, Khao Nan, T. Boonkerd, Y. Sirijamorn & C. Sanguansab 58 (BCU); Chanthaburi, Khao Soi Dao, T. Shimizu et al. T-23921 (L). INDONESIA. Java, PE-BO Team 28 (K). MALAYSIA. Pahang, A.G. Piggott 2424 (K); ibis., A.G. Piggott 2427 (K); Pahang, B. Molesworth-Allen 2929 (K); no locality, B.E.G. Molesworth-Allen 1328 (BM); Pahang, B.E.G. Molesworth-Allen 1712 (BM); Pahang, B.S. Parris 10583 (K); Perak, C.G. Matthew s.n. (K); Perak, H.C. Robinson s.n. (K); Selangor, H.N. Ridley 7844 (K); Perak, J. Day s.n. (K); Pahang, K.M. Wong 35205 (K); Perak, R. Jaman & Z. Mohamad 4148 (K); Pahang, R.E. Holttum 31350 (K); ibis., R.E. Holttum SFN23338 (K).

Figures

FIGURE 32. Diplazium subintegrum Holttum. A, lamina. B, a part of pinna with sori. C, scale showing entire and not black marginal cells with minutely caducous membrane. P. Pongkai 67 (BCU).