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 14. Diplazium mixtum (Roxb.) C.V. Morton (1974: 294) . Fig. 17 . Asplenium mixtum Roxburgh (1844: 499) . TYPE : INDONESIA . Ambon ?, anon. s.n. ( C . Smith?) ( lectotype BR [ BR0000006989866 ], designated by Morton (1974)) . Asplenium prescottianum Wallich ex Hooker (1860: 251) . Diplazium prescottianum (Wall. ex Hook.) T. Moore (1859: 334) . Type : SINGAPORE . 1922, Wallich , 235 ( lectotype K-W [ K001109599 ], designated by Morton (1974) ; isolectotypes K000443459 !, K000443460 !). Plants terrestrial. Stems erect, 5–6 cm diameter, bearing thick black roots, apex scaly; scales about 15 × 1 mm , narrowly lanceolate, concolorous, dark brown, margin entire. Fronds up to 1.30 m , imparipinnate; petioles 60–80 cm , 5–6 mm diameter, glabrous, green with dark brownish base. Laminae 43–50 × 18–25 cm , outline oblong, suddenly becoming smaller upword, long acuminate apex, terminal pinna not distinct, glabrous, papyraceous, deep green; lateral pinnae 11–12 pairs, alternate, 13–17 × 1.7–2.0 cm, bolong, falcate, apex caudate-attenuate, base obtuse, margin crenate, moderately auricle at acroscopic base; aucicle, apex round to obtuse, margin subentire, stalked; stalk 2.0– 2.5cm , longest at lower pinnae; veins pinnate, veinlets 3–4 pairs. Sori 0.5–1.0 cm, elongate along veinlets, diplazoid, indusiate; indusia thin, firm, persistance. Spores monolete, 40.5–43.0 × 23.5–25.5 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: labryrinth. FIGURE 16. Diplazium mettenianum (Miq.) C.Chr. A , lamina. B, a part of pinna with sori. C, scale showing entire and not black marginal cells. P. Pongkai 2 0 (BCU). FIGURE 17. Diplazium mixtum (Roxb.) C.V. Morton. A , frond. B, a part of pinna with sori. C, scale showing entire and not black marginal cells. J. Sinclair 9376 (SING). Thailand : —SOUTH-EASTERN: Trat (Ko Chang) ; PENINSULAR: Nakhon Si Thamarat (Khao Luang), Yala (Ban Chana, Ban Malao). Distribution : — Malaysia , Singapore. Ecology: — On humus-rich mountain slopes in dense evergreen forests at medium elevations. Specimens Examined :— THAILAND . Prachinburi , Khao Yai , K. larsen, T. Smitinand & E. Warncke 312 ( BKF ) ; MALAYSIA . Perak , Anonymous s.n. ( K ). SINGAPORE . Crangie, H . J . Murton 100 ( K ); Tanjong Gul, J . Sinclair 9376 ( K ); no locality, N . Wallich 235 ( K ); ibis., T . Lobb 32 ( K ).