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 283833 10.11646/phytotaxa.631.1.1 4aedceb1-f224-4ad0-a840-4e167b57ae2d 1179-3163 10422862 11. Diplazium leptophyllum Christ ex C. Christensen (1913: 106) . Fig. 14 . Type: CHINA . Yunnan , Szemao , A . Henry 13106 ( lectotype MO-2140172 / A : 1194 !; designated here; isolectotype K00189421 !, MO-255735 / A : 1195 !, P01564505 !!) . Plants terrestrial. Stems short creeping, 1.0– 1.5 cm diameter, scaly; scales 10–12 × 1.0– 1.5 mm , linear, concolorus, dark brown to nearly black, margin entire. Fronds up to 1.20 m , bipinnate to bipinnate-tripinnatifid; petioles 30–50 cm , glabrous, dark green, dark at lower portion, groove above. Laminae 60–70 × 50–60 cm , subdeltoid in outline, terminal pinna not distinct, glabrous, papyraceous, light green; pinnae 6–8 pairs, alternate, 25–30 × 12–15 cm , oblong in outline, apex acuminate, stalked; stalks 1.5–2.0 cm; pinnule 12–14 pairs, alternate, 5–6 × 2.5–3.0 cm, subdeltoid, apex acuminate, base subtruncate to truncate; lobed at margin; lobes ¾ way to costule, apex round, margin serrate, shortly stalked; veins pinnate, veinlets 4–5 pairs, free, simple or once forked. Sori 3–5 mm , elongate along veinlets, diplazoid, usually on basal veinlets of vein group. Spores monolete, 30.0–37.5 × 17.5–20.0 μm, bilateral, concavo-convex to plano-convex, perispore present; ornamentation: echinate. Thailand: —NORTHERN: Chiang Mai (Doi Chiang Dao, Doi Suthep, Mae Jam), Chiang Rai (Mae Lao), Lamphun (Doi Khun Tan) . Distribution: — India , Bhutan , China and Myanmar . Ecology: —On moist ground or on mountain slopes in dense mixed or evergreen forests at 850–1,600 m elev. Specimens Examined:— THAILAND . Chiang Mai , Doi Suthep, J.F. Maxwell 89-855 (L); Lampoon, Doi Khun Dan, J.F. Maxwell 93-771 (L); Chiang Mai , Mae Jam, J.F. Maxwell 98-1444 (L); Chiang Mai , Chiang Dao, M. Shimizu & M Hutoh T4396 (L); ibis., M. Shimizu & M Hutoh T10210 (L); ibis., M. Shimizu & M Hutoh T10210 (BKF); Chiang Mai , Chiang Dao, M. Tagawa & K. Iwatsuki T4396 (BKF); Lamphun , Doi Khun Tan, M. Tagawa T9324 (L); Chiang Mai , Chiang Dao, P. Pongkai 78 (BCU); ibis., P. Pongkai 79 (BCU); ibis., P. Pongkai 80 (BCU); Chiang Mai , Doi Suthep, S. Premwichit 5 (L). CHINA . Yunnan , A. Henry 13106 (B, K). INDIA . Manickam RHT34384 (K); Manickam 31083 (K); Manickam 582 (K).