Diplazium dilatatum Blume (1828: 194)

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 : 17-19

5. Diplazium dilatatum Blume (1828: 194) . Fig. 8 .

Type: INDONESIA. Java, Blume s.n. (lectotype L0051552 !, designated here; isolectotype K000472211 !) .

Plants terrestrial. Stems massive, erect, densely covered with scales at apex; scales about 10–15 × 1–2 mm, linear with long tail apex, brown to dark brown, margin thick and toothed. Fronds 1.5–1.7 m, bipinnate; petioles 50–70 cm, 1.0– 1.5 cm diameter, darkgreen, black at lower portion, densely scaly at base, grooved above. Laminae 1.0 × 0.6–0.7 m, deltoid in outline, terminal pinna not distinct; pinnae 6–10 pairs, alternate, 20–30 × 10–20 cm, stalks distinct, 1.0– 1.2 cm, oblong in outline, apex acuminate, hairy along the rachis and underneath the leaves, papyraceous, green; pinnules 10–12 pairs, alternate, 8–10 × 2.0– 2.5 cm, sessile or shortly stalked, oblong, apex acuminate, base subtruncate, truncate to cordate, margin subentire to lobed; lobes ¼ to ½ way to costule; veins all free, veinlets 4–6 pairs simple or once forked. Sori 4–5 mm, elongate along veinlets, usually more than 5 mm long, diplazoid, indusiate; indusia thin, firm, persistant. Spores monolete, 40.5–45.0 × 25.0–29.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds.

Thailand: —NORTHERN: Chiang Mai (Doi Chiang Dao, Doi Khun Huai Pong, Doi Suthep, Kang Kat, Doi Inthanon), Chiang Rai (Doi Pacho, Doi Langka, Mae Kok), Nan (Doi Phu Ka), Tak (Ban Musoe, Mae Sod, Umm Paang), Phitsanulok (Thung Salang Luang, Phu Rom Rot), Sukhothai (Ram Kham Heang National Park), Nakhon Sawan (Doi Musae); NORTH-EASTERN: Phetchabun (Phu Maing, Kaeng Ratchapruk), Loei (Na Haeo, Puh Kradueng, Phu Luang); EASTERN: Nakhon Ratchasima (Sa kaerat); SOUTH-WESTERN: Uthai Thani (Ban Rai), Kanchanaburi (Khao Ngi Yai), Prachuap Khiri Khan (Huaiyang waterfalls); CENTRAL: Nakhon Nayok (Khao Yai); SOUTH-EASTERN: Prachin Buri (Khao Yai), Chanthaburi (Khao Soi Dao); PENINSULAR: Surat Thani (Khao Khieo range), Phangnga (Khao Pok), Nakhon Si Thammarat (Khao Luang, Khao Nan), Trang (Khao Chong), Satun, Yala (Muang Wing) .

Distribution: — India, Nepal, China, Taiwan Island, Japan, Myanmar, Laos, Vietnam, Malaysia, Philippines, Indonesia and Australia.

Ecology: —On moist or humus-rich mountain slopes in dense gloomy forests at 400–1,500 m elev.

Specimens examine:— THAILAND. Satun, A.F. G. Kerr 14561 (BK); Nakhon Ratchasima, A.F. G. Kerr 9928 (BM); Nakhon Ratchasima, A.F. G. Kerr 9928 (BK); Chiang Mai, Doi Inthanon, C. Phengklai et al. 7135 (L); Loei, Phu Luang C.F. van Beusekom & C. Phengklai 3074 (L); Guangdong, C.G. Matthew s.n. (K); Nakhon Sawan, Doi Musae, E. Hennipman 3005 (L); Chiang Mai, Doi Suthep, E. Hennipman 3132 (L); Chiang Mai, Doi Suthep, E. Hennipman 3132 (B); Loei, Phu Luang, E. Hennipman 3590 (L); Prachinburi, Khao Yai, E. Hennipman 3969 (L); Nakhon Sawan, Doi Musae, E. Hinnapman 3005 (BM); Chiang Mai, Doi Inthanon, E. Hinnapman 3006 (BM); no locality Hansen & Smitinand 12811 (K) Chiang Mai, Doi Suthep, J.F. Maxwell 90-282 (L); Chiang Mai, Doi Inthanon, J.F. Maxwell 93- 109 (L); Chiang Mai, Doi Suthep, J.F. Maxwell 93-747 (L); Sukhothai, Ram Kham Heang National Park, J.F. Maxwell 95-51 (L); Chiang Rai, Doi Langka, K. Iwatsuki & N. Fukuoka T3568 (L); Chiang Mai, Doi Suthep, K. Iwatsuki & N. Fukuoka T3960 (L); Chantaburi, Khao Soi Dao, K. Iwatsuki & N. Fukuoka T7184 (L); Chiang Rai, along Nam Mae Kok, K. Iwatsuki, N. Fukuoka, M. Hutoh & D. Chaiglom T10916 (L); Chiang Mai, Doi Suthep, M. Tagawa T3849 (L); Loei, Phu Luang, M. Tagawa , K. Iwatsuki & N. Fukuoka T1269 (L); Chiang Mai, Doi Inthanon, M. Tagawa , K. Iwatsuki & N. Fukuoka T2654 (L); Chiang Mai, Doi Suthep, M. Tagawa , K. Iwatsuki & N. Fukuoka T31 (L); Trang, Khao Chong, M. Tagawa , K. Iwatsuki & N. Fukuoka T6832 (L); Tak, Ban Musae, M. Tagawa , K. Iwatsuki, H. Koyama & A. Chintayungkun T8608 (BKF, L); Nan, Doi Phu Ka, P. Pongkai 10 (BCU); Phitsanulok, Phu Hin Rong kla, P. Pongkai 13 (BCU); ibis., P. Pongkai 14 (BCU); Loei, Phu Kradueng, P. Pongkai 24 (BCU); Nakhorn Si Thammarat, Khao Nan, P. Pongkai 41 (BCU); Nakhorn Si Thammarat, Krung Ching waterfalls, P. Pongkai 51 (BCU); Nakhon Si Thammarat, Khao Luang, P. Pongkai 55 (BCU); ibis., P. Pongkai 132 (BCU); Nan, Doi Phuka, P. Pongkai 149 (BCU); Chiang Rai, Khunkorn waterfalls, P. Ratchata 288 (BCU); Phitsanulok, Phu Hin Rong kla, P. Suksathan 1355 (QBG); Chanthaburi, Khao Soi Dao, P. Suksathan 4423 (QBG); Phitsanulok, Phu Hin Rong kla, Pteridophyte Trip 85 (BCU); Nakhon Ratchasima, Put 3579 (BK, BM), Ratchaburi, Suan Phueng, Suan Phueng trip 169 (BCU); Mae Sod, T. Boonkerd 1213 (BCU); Tak, Uum Paang, T. Boonkerd 1339 (BCU); Nakhon Ratchasima, Sa kaerat, T. Boonkerd 533 (BCU); Nakhorn Si Thammarat, Khao Nan, T. Boonkerd, Y. Sirijamorn & C. Sanguansab 176 (BCU); Petchchabun, Kaeng Ratchapruk, T. Nachol 44 (BCU); Phetchabun, Phu Miang, T. Shimizu et al. T11360 (L); Loei, Phu Kradueng,, T. Shimizu et al. T23038 (L); No locality, T. Smitinand 6053 (K); Loei, Na Haeo, W. Nanakorn 8080 (QBG); Phitsanulok, Phu Hin Rong kla W. Rattanathirakul 57 (BCU); Prachuap Khiri Khan, Huaiyang waterfalls, Y. Yuyen 21 (BCU). CHINA. Guangdong, C.G. Matthew s.n. (K); no locality, Tsang 534 (K); ibis., 15907 (K). INDONESIA. Ruteng, A J.G.H. Kostermans & Wirawan 666 (K); Jawa, C.L.Blume s.n. (K); Kalimantan, M. Kato, G. Murata & Y.P Mogea B3738 (K). MALAYSIA. Pahang, A.G. Piggott 2977 (K); Pahang, B. Molesworth-Allen 3325 (K); Sabah B.S. Parris & J.P. Croxall 8913 (K); Sabah, J.H. Beaman, R.S. Beaman & T.E. Beaman 10641 (K); Pahang, M.R. Henderson 23620 (K); Sabah, P.S. Shim San74948 (K); Pahang, R.E. Holttum 31334 (K); Sarawak, W.L. Chew 1037 (K). NEPAL. no locality, N. Wallich 203 (K); ibis., N. Wallich 209 (K). PAPUA NEW GUINEA. Morobe, B.S. Parris & J.P. Croxall 4448 (K); Northern District, C.E. Carr 15712 (K); East New Britain, G. Boyce 18 (K); South New Ireland, J.R. Croft 1961 (K); Northern District, R.D. Hoogland 4179 (K).

Note: —According to Holttum (1960), Diplazium dilalatum and D. simplicivenium are differed in venation and stalk of pinnules.

Figures

FIGURE 8. Diplazium dilatatum Blume. A, pinna. B, a part of pinnule with sori. C, scale showing toothed and black marginal cells. P. Pongkai 14 (BCU).