4. Diplazium cordifolium Blume (1828: 190). Fig. 7. Type: INDONESIA. Java, Kapala Tjibeureum, J. C. Van Hasselt s.n. (lectotype L0051534, designated by Hovenkamp 2019: 61). Plants terrestrials. Stems erect, 1–2 cm diameter, apex covered with scales; scales 6–12 × 1–1.5 mm, narrowly lanceolate with long tail apex, margins thick, dark brown, margin entire. Fronds 65–70 cm, usually simple or sometime imparipinnate; petioles up to 40 cm, 3–5 cm diameter, dark green when living, stramineous to brown when dried, lower part black, grooved above. Laminae, simple laminae, 25–30 × 8–12 cm, cordate or narrowly cordate, apex acuminate, base cordate, margin subentire to undulate, glabrous, coriaceous, dark green; midrib distinctly raised beneath, glabrous; veins branching a few times near midrib and uniting to form irregularly-anastomosing vein near margin; gemmae usually present at base of lamina between stipe and midrib; imparipinnate lamina, 25–30 × 14–20 cm, ovate in outline, terminal pinna present, usually bigger than lateral ones, 12–15 × 4–5 cm, ovate-lanceolate, apex acuminate, base obtuse, margin entire to subentire; lateral pinnae 3–4 pairs, alternate, 10–15 × 3–5 cm, becoming smaller upward, lower pinnae largest, sessile, bearing gemmae at junction between rachis and costa, ovate-lanceolate, apex acuminate, base cordate to obtuse, margin subentire, glabrous, coriaceous, dark green; vein anastomosing. Sori up to 4 cm, elongate along anastomosing veinlets, on both side of each veinlet, indusiate; indusia thin but persistent; spore monolete, 47.5–50 × 35–45 µm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds. Thailand: —PENINSULAR: Chumphon (Lang Suan), Nakhon Si Thammarat (Khao Luang, Khao Nan), Trang (Khao Chong, Khao Pad Pha), Narathiwat (Ban Phu Klong Thong, Waeng), Pattani, Songkhla, Yala (Ban Chana). Distribution: — Malaysia, Indonesia, Singapore, Australia and Papua New Guinea. Ecology: —On moist sandy mountain slopes in dense gloomy forests at 800–1,100 elev., locally fairly abundant. Specimens Examined:— THAILAND. Chumphon, Lang Suan, A.F. G.Kerr 12008 (BK,BM); Trang, C.Apasutaya 125 (BCU); Nakhon Si Thammarat, Khao Luang, C. Thorat 135 (BCU); Nakhon Si Thammarat, Khao Luang, C.F. van Beusekom & C. Phengklai 944 (L, PE); Nakhon Si Thammarat, Khao Luang, E. Hennipman 3815 (BKF, BM, L); Nakhon Si Thammarat, Khao Luang, K. Larsen et al. 45926 (L, QBG); Trang, Khao Chong, M. Tagawa, K. Iwatsuki & N. Fukuoka T4631 (L); Nakhon Si Thammarat, Khao Luang, M. Tagawa, K. Iwatsuki & N. Fukuoka T4833 (L); Trang, Khao Chong, M. Tagawa, K. Iwatsuki & N. Fukuoka T6816 (L); Songkhla, Ton Nga Chang waterfalls, N. Putthisawong 36 (PSU); Nakhorn Si Thammarat, Khao Nan, P. Pongkai 34 (BCU); ibid., P. Pongkai 37 (BCU); ibid., P. Pongkai 42 (BCU); Nakhon Si Thammarat, Khao Luang, P. Pongkai 60 (BCU); ibid., P. Pongkai 121 (BCU); Nakhon Si Thammarat, Khao Luang, P. Suksathan 1067 (QBG); Trang, Khao Pad Pha, R. geesink, T. Haltink & C.C. Charaenpol 7286 (L); Nakhon Si Thammarat, Khao Luang, S. Sutisorn 824 (BK); Narathiwat, Ban Phu Klong Thong, T. Boonkerd 1516 (BCU); Nakhon Si Thammarat, Khao Luang, T. Boonkerd s.n. (BCU); Nakhorn Si Thammarat, Khao Nan, T. Boonkerd, Y. Sirijamorn & C. Sanguansab 8 (BCU); ibid., T. Boonkerd, Y. Sirijamorn & C. Sanguansab 240 (BCU); ibid., T. Boonkerd, Y. Sirijamorn & C. Sanguansab 491 (BCU). INDONESIA. Seram Manusela National Park, B.S. Parris 11121 (K); Java, Blume s.n. (L); Sulawesi, E. Hennipman 5195 (K); Kalimantan, K. Iwatski, M. Kato, G. Murata & Y.P. Mogea B2171 (K); Seram Manusela National Park, M. Kato, K. Ueda & U.W. Mahjar C1220 (K); Seram Manusela National Park, M. Kato, K. Ueda & Z. Fanani C11676 (K); Borneo, R.E. Holttum 25139 (PE); ibid., R.E. Holttum 25140 (PE); Pahang, R.E. Holttum 31219 (PE); Jaya, R.J. Johns 8189 (K). MALAYSIA. Pahang, A.G. Piggott 2994 (K); Pahang, A.G. Piggott 3103 (K); Kinabalu, B.S. Parris & J.P. Croxal 9131 (K); Sarawak, B.S. Parris 6470 (K); Sarawak, B.S. Parris 6629 (K); Perak, C.G. Matthew s.n. (K); Penang, C.G. Matthew s.n. (K); Sabah, G. Stort & P. van Amdjah 359 (K); Perak, J. Sinclair & Kiah 38745 (K); Sabah, P.S. Shim San75407 (K); Sabah, Pearce 3 (K); no locality, R. Schlechter 17821 (PE); Penang, W. Norris 19 (K); Penang, W.B. Lorrain s.n. (K). PAPUA NEW GUINEA. Morobe, A. Kairo 26 (K); Torricelli Mts., F.R.R. Schlechter 14404 (K); Kaiser-Wilhelmsland Ibo Mountains, F.R.R. Schlechter 17821 (K); Madang, H.J. Gay & F.J. Parrott 671 (K); Morobe, J. Manseima 10 (K); Manus Island, M.J.S. Sands G.A. Pattison & J.J. Wood 2923 (K); Morobe, T. Nakaike 54 (K); Morobe, W. Takeuchi 7396 (K); East Sepik Province, W. Takeuchi et al. 17862 (K). PHILIPPINES. Mindoro Subaan River, Ridsdale, Coode & Reynoso 5585 (K). Note: —This species has two forms of fronds but pinnate frond is rarely found.

Published as part of Pongkai, Puttamon, Zhang, Li-Bing, Boonkerd, Thaweesakdi & Pollawatn, Rossarin, 2023, Revision of the fern genus Diplazium (Polypodiales: Athyriaceae) in Thailand, pp. 1-69 in Phytotaxa 631 (1) on pages 14-17, DOI: 10.11646/phytotaxa.631.1.1, http://zenodo.org/record/10422862