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 21. Diplazium procumbens Holttum (1940: 95) . Fig. 27 . Type : MALAYSIA . Pahang , R . E . Holltum 36503 ( holotype K000443463 !) . Plants terrestrial. Stems creeping, 1.5–2.0 cm diameter, densely covered with scales at apex; scales 8–10 × 0.7–1.0 mm, linear with long tail apex, concolorous, brown, margin toothed. Fronds up to 1.4–1.6 m , bipinnate; petioles 70–80 cm , 5–6 mm diameter, glabrous, deep green, dark at lower portion. Laminae 75–80 × 67–72 cm , deltoid in outline, gradually narrowing upwards, long acuminate apex, glabrous, papyraceous, light green; pinnae 45–50 × 18–20 cm , alternate, oblong in outline stalked; stalks 2.5–3.0 cm, largest at lower pinnae; pinnules 8–9 ×2.0– 2.5 cm , alternate, oblong, apex long acuminate to attenuate, base truncate, lobed at margin; lobes about ¾ way to costule, apex obtuse, margin subentire to dentate, stalked; stalks 1–2 mm ; veins pinnate, 4–5 pairs, free, once forked. Sori 2–4 mm , elongate along veinlets, diplazoid, close to midrib, indusiate; indusia linear, very thin, persistance. Spores monolete, 47.5–57.5 × 25.0–32.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: prominent wing folds. Thailand : —SOUTH-WESTERN: Petchaburi (Kaeng Krachan National Park); Prachuap Khiri Khan (Khao Luang). Distribution: — Sri Lanka , Malaysia . Ecology: —On moist and shady area, near stream at about 1,300 m elev. Specimens Examined:— THAILAND . Phetchaburi , Kaeng Krachan, D.J. Middleton et al. 1762 (BKF). MALAYSIA . Pahang , B.E.G. Molesworth-Allen 1439 (BM); Pahang , R.E. Holltum 21645 (K); ibis., R.E. Holltum 21646 (K); ibis., R.E. Holltum 36503 (K). SRI LANKA . Namunukula, W.A. Sledge 1192 (BM, K). Note: —This species is a new record for the Flora of Thailand .