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 Key to the species of Diplazium in Thailand 1a Fronds simple .....................................................................................................................................................................................2 1b Fronds compound ...............................................................................................................................................................................3 2a Lamina cordate; scale margins entire ...................................................................................................................... 4. D. cordifolium 2b Lamina oblong; scale margins toothed................................................................................................................. 27. D. subserratum 3a Fronds unipinnate ...............................................................................................................................................................................4 3b Fronds bipinnate ...............................................................................................................................................................................23 4a Rhizome creeping...............................................................................................................................................................................5 4b Rhizome erect.....................................................................................................................................................................................8 5a Upper pinnae not reduced; terminal pinna distinct…………………………………………….........................................................6 5b Upper pinnae gradually reduced; terminal pinna not distinct……………………………........ ........................................................7 6a Terminal pinna simple ................................................................................................................................................ 6. D. donianum 6b Terminal pinna pinnatifid .................................................................................................................................... 29. D. thailandicum 7a Veinlets simple or once forked, 3–4 pairs; sori cresentic, 2–3 mm long.......................................................................... 18. D. petrii 7b Veinlets all free, 4–5 pairs; sori elongate along vein, 4–5 mm long ................................................................... 13. D. mettenianum 8a Scales entire........................................................................................................................................................................................9 8b Scales toothed...................................................................................................................................................................................12 9a Terminal pinna not distinct...............................................................................................................................................................10 9b Terminal pinna distinct .....................................................................................................................................................................19 10a Stipes and rachis tomentose................................................................................................................................... 30. D. tomentosum 10b Stipes and rachis glabrous ................................................................................................................................................................11 11a Auricle at basiscopic base of pinnule distinct; pinnae-stalks 4–5 mm long…..…….……..……................................ 14. D. mixtum 11b Auricle not distinct; pinnae-stalks less than 3 mm long............................................................................................... 9. D. holttumii 12a Terminal pinna distinct .....................................................................................................................................................................13 12b Terminal pinna not distinct...............................................................................................................................................................15 13a Lateral pinnae 10–15 pairs; terminal pinna subdeltoid, unlike lateral pinnae; lobed at margin.......................................................14 13b Lateral pinnae 3–5 pairs; terminal pinna similar to lateral one, entire at margin.................................................... 1. D. bantamense 14b Veins anastomosing; pinnae subentire to crenate at margin; gemmae absent .................................................... 12. D. megaphyllum 14b Veins free; pinnae serrate at margin; gemmae usually present between rachis and pinnae .................................... 22. D. proliferum 15a Veins all free .....................................................................................................................................................................................16 15b Veins anastomosing .................................................................................................................................................. 7. D. esculentum 16a Pinnae subentire or crenate at margin; auricle present at acroscopic base.......................................................................................17 16b Pinnae lobed at margin; auricle absent…….....................................................................................................................................18 17a Veinlets 1–2 pairs; pinnules 2.5–4 cm broad; distinctly auricled at base................................................................ 19. D. phanerotis 17b Veinlets 3–4 pairs; pinnules 1–1.5 cm broad; moderately auricled at base ............................................................ 28. D. sylvaticum 1 ∗ Following floristic format, references like this are not listed in References but can be found in Tropicos or IPNI. 18a Pinnae suddenly becoming smaller upwards, stalks up to 2 cm long ....................................................................... 23. D. siamense 18b Pinnae gradually becoming smaller upwards, stalks less than 0.5 cm long........................................................ 25. D. sorzogonense 19a Lateral pinnae more than 10 pairs; pinnae 2 cm wide; veins all free ...............................................................................................20 19b Lateral pinnae less than 7 pairs; pinnae more than 3 cm wide; veins anastomosing .......................................................................21 20a Veinlets 1 pairs, stalks 1–2 mm long.......................................................................................................................... 16. D. pallidum 20b Veinlets more than 1 pairs, stalks more than 3 mm long...................................................................................... 26. D. subintegrum 21a Pinnae ovate-lanceolate, long acuminate at apex, obtuse at base; gemmae usually present at junction between rachis and base of pinnae ...................................................................................................................................................................... 4. D. cordifolium 21b Pinnae oblong, acuminate at apex, acute at base; gemmae absent………………….…..................................................................22 22a Fronds less than 40 cm long; pinnae 2–4 pairs...................................................................................................... 8. D. fraxinifolium 22b Fronds up to 60 cm long; pinnae 4–7 pairs ........................................................................................................ 31. D. xiphophyllum 23a Rhizome creeping ............................................................................................................................................................................25 23b Rhizome erect or ascending..............................................................................................................................................................27 24a Scales with black margin....................................................................................................................................... 3. D. conterminum 24b Scales concolorous ...........................................................................................................................................................................25 25a Sori curved or cresentic usually lie on acroscopic veinlets of vein group .......................................................................................26 25b Sori oblong, usually lie on all veinlets .................................................................................................................. 21. D. procumbens 26a Sori submarginal, 2–3.5 mm long .................................................................................................................................... 18. D. petrii 26b Sori close to costule, 3–5 mm long ..................................................................................................................... 11. D. leptophyllum 27a Scales with black margins ...............................................................................................................................................................28 27b Scales with no black margins ..........................................................................................................................................................33 28a Sori oblong, usually less than 3 mm long.........................................................................................................................................29 28b Sori linear, usually more than 5 mm long .......................................................................................................................................30 29a Sori close to midrib of lobe ................................................................................................................................ 19. D. polypodioides 29b Sori medial between margin and midrib of lobe ................................................................................................... 10. D. kappanense 30a Veins free; pinnules lobed at margin ...............................................................................................................................................31 30b Veins anastomosing; pinnules subentire at margin................................................................................................... 7. D. esculentum 31a Pinnule sessile, base subtruncate to truncate....................................................................................................................................32 31b Pinnules stalked, base minutely cordate...................................................................................................................... 5. D. dilatatum 32a Pinnules crenate to lobe at margin, apexlong-acuminate ................................................................................. 24. D. simplicivenium 32b Pinnules subentire to serrate at margin, apex acute to acuminate ................................................................................ 17. D. petelotii 33a Pinnae and pinnule subopposite to opposite; sori close to costule.................................................................................. 2. D. bellum 33b Pinnae and pinnule alternate; sori not close to costule............................................................................................ 15. D. muricatum