Revision of the fern genus Diplazium (Polypodiales: Athyriaceae) in Thailand Author Pongkai, Puttamon 0000-0003-0273-1889 Office of National Science Research, National Science Museum, Technopolis, Khlong 5, 39 Moo 3, Khlong Luang, Pathum Thani, 12120, Thailand. & Puttamon. p @ nsm. or. th; https: // orcid. org / 0000 - 0003 - 0273 - 1889 uttamon.p@nsm.or.th Author Zhang, Li-Bing 0000-0002-4905-040X Missouri Botanical Garden, P. O. Box 299, St. Louis, Missouri 63166 - 0299, USA and Chengdu Institute of Biology, Chinese Academy of Sciences, P. O. Box 416, Chengdu, Sichuan 610041, China & Libing. Zhang @ mobot. org; https: // orcid. org / 0000 - 0002 - 4905 - 040 X hang@mobot.org Author Boonkerd, Thaweesakdi 0009-0001-5864-7208 Office of National Science Research, National Science Museum, Technopolis, Khlong 5, 39 Moo 3, Khlong Luang, Pathum Thani, 12120, Thailand. & Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. & bthawees @ googlemail. com; https: // orcid. org / 0009 - 0001 - 5864 - 7208 bthawees@googlemail.com Author Pollawatn, Rossarin 0000-0001-6798-7274 Office of National Science Research, National Science Museum, Technopolis, Khlong 5, 39 Moo 3, Khlong Luang, Pathum Thani, 12120, Thailand. & Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. & Office of National Science Research, National Science Museum, Technopolis, Khlong 5, 39 Moo 3, Khlong Luang, Pathum Thani, 12120, Thailand. & Rossarin. p @ chula. ac. th; https: // orcid. org / 0000 - 0001 - 6798 - 7274 * Corresponding authors: Puttamon. p @ nsm. or. th; Libing. Zhang @ mobot. org & Office of National Science Research, National Science Museum, Technopolis, Khlong 5, 39 Moo 3, Khlong Luang, Pathum Thani, 12120, Thailand. ossarin.p@chula.ac.th text Phytotaxa 2023 2023-12-22 631 1 1 69 https://phytotaxa.mapress.com/pt/article/download/phytotaxa.631.1.1/51384 journal article 10.11646/phytotaxa.631.1.1 1179-3163 10422862 24. Diplazium simplicivenium Holttum (1940: 100) . Fig. 30 . Type: MALAYSIA . Pahang , Holttum, R.E . 36507 ( holotype SING !; isotype K000443625 !) . Plants terrestrial. Stems massive, erect, 5–8 cm diameter, densely scaly at apex; scale 1.8–2.0 × 0.15–0.20 cm , linear, long tail at apex, brown, margin thick and toothed. Fronds 1.8–2.4 m , bipinnate; petioles 0.8–1.0 m, 1.5–2.0 diameter, deep green, densely scaly at base. Laminae 1.0–1.4 × 0.8–1.0 m, ovate–deltoid, terminal pinna not distinct; pinnae 6–8 pairs, alternate, 54–60 × 25–28 cm , stalked; stalk about 1 cm , oblong in outline, apex acuminate, glabrous, papyraceous, green; pinnules 12–14 pairs, alternate, 10–12 × 2.0– 2.5 cm , sessile, oblong, apex long acuminate, base truncate, margin shallowly lobed; lobes less than ¼ way to midrib of pinnules, 5–8 mm broad subquadrangular, apex obtuse, margin subentire; veins free, pinnate, 5–6 pairs of each vein group. Sori usually more than 5 mm long, elongate along veinlets, diplazoid, indusiate; indusia thin, firm, persistant. Spores monolete, 51.0–54.5 × 30.5–34.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds. Thailand: —NORTHERN: Chiang Mai (Doi Inthanon), Tak (Umm Phang);ESTERN: Nakhon Ratchasima (Sa Kaerat); SOUTH-WESTERN: Kanchanaburi (Khao Ngi Yai, Khao Yai, Thong Pha Phum), Uthai Thani (Ban Rai); SOUTH-EASTERN: Chon Buri (Khao Kiew); PENINSULAR: Surat Thani (Klong Ton), Nakhon Si Thammarat (Khao Luang, Khao Nan), Phangnga (Khao Pok), Trang (Khao Chong), Satun, Yala (Muang Wing) . Distribution: — Myanmar , Malaysia Philippines and Indonesia . Ecology: —On moist mountain slopes in dense evergreen forests at medium elevations at 400–1500 m elev. Specimens Examined:— THAILAND . Kanchanaburi , Thong Pha Phum, A. Sathapattayanon 122 (BCU); Kanchanaburi , A.F. G. Kerr 10422 (BK); Satun , A.F. G. Kerr 10477 (BK); Trung, Khao, Chong, C. Apasutaya 122 (BCU); Trang , Khao Chong, C. Charoenphol, K. Larsen & E. Warncke 3707 (L); Kanchanaburi , Khao Yai, C.F. van Beusekom & C. Phengklai 290 (L); Uthai Thani , C.F. van Beusekom & T. Santisuk 2894 (L); no locality, C.F. van Beusekom & T. Santisuk 2894 (K); Chiang Mai , Doi Inthanon, E. Hennipman 3458 (BKF); ibis., E. Hennipman 3458 (B); Chon Buri , Khao kiew, J.F. Maxwell 75-665 (L); Chonburi , J.F. Maxwell 75-665 (BK); Trang , Khao Chong, M. tagawa & I. Yamada T 202 (L); Nakhon Si Thammarat , Khao Luang, M. Tagawa , K. Iwatsuki & N. Fukuoka T4803 (L); Chiang Mai , Doi Inthanon, P. Pongkai 94 (BCU); Nakhon Si Thammarat , Khao Luang, P. Pongkai 123 (BCU); ibis., P. Pongkai 95 (BCU); ibis., P. Pongkai 96 (BCU); Nakhon Ratchasima , Sa kaerat, T. Boonkerd 534 (BCU); Tak , Um Phang, T. Boonkerd 1848 (BCU); Nakhon Si Thammarat , Khao Nan , T. Boonkerd, S. Chantanaorapint & W. Khwaiphan 420 (BCU); Nakhon Si Thammarat , Khao nan, T. Boonkerd, Y. Sirichamorn & C. Sanguansab 151 (BCU); ibis., T. Boonkerd, Y. Sirichamorn & C. Sanguansab 208 (BCU); Trang , Khao Chong, T. Shimizu et al. T27456 (L); Kanchanaburi , T. Vongthavone 66 (BK); MYANMAR . Tenasserim Division, Tawer, J.F. Maxwell 98-327 (L); MALAYSIA . Pahang , A.G. Piggott 3116 (K); Selangor , B. Molesworth-Allen 4151 (K); Perak , B. Molesworth-Allen 4369 (K); Pahang , B.E.G.Molesworth-Allen 8329 (BM); Perak , Dr. King’s Collector 2214 (K); ibis., Dr. King’s Collector 2346 (K); ibis., Dr. King’s Collector 8420 (K); Perak , H.N. Ridley 12411 (K); Selangor , B. Molesworth-Allen, (K); Pahang , R. Jaman et al. RJ6011 (PE); Pahang , R.E. Holttum 36507 (K); ibis., R.E. Holttum SFN21636 (K); PHILIPPINES . Rizal , M. Ramos 956 (K); INDONESIA . Borneo, A.C. Jermy & J.M. Rankin J14840 (BM); Sumatra , J.A. Lörzing 15667 (K).