The moss family Rhachitheciaceae (Dicranales, Bryophyta) in Thailand Author Chantanaorrapint, Sahut 0000-0002-9739-0994 Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand & sahut. c @ psu. ac. th; https: // orcid. org / 0000 - 0002 - 9739 - 0994 sahut.c@psu.ac.th Author Sevanakun, Nilobon 0000-0003-0839-8749 Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand & nilobon. sev @ gmail. com; https: // orcid. org / 0000 - 0003 - 0839 - 8749 nilobon.sev@gmail.com Author Suwanmala, Orawanya 0000-0002-1113-7614 Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand & o. suwanmala @ gmail. com; https: // orcid. org / 0000 - 0002 - 1113 - 7614 o.suwanmala@gmail.com Author Sukkharak, Phiangphak 0000-0001-5330-1411 Department of Biology, Faculty of Science, Burapha University, Chonburi 20131, Thailand & phiangphak @ buu. ac. th; https: // orcid. org / 0000 - 0001 - 5330 - 1411 phiangphak@buu.ac.th Author Printarakul, Narin 0000-0001-5979-0199 Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand & kamenpcobtor @ gmail. com; https: // orcid. org / 0000 - 0001 - 5979 - 0199 kamenpcobtor@gmail.com Author He, Si 0000-0001-6560-6933 Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, MO 63110, U. S. A. & si. he @ mobot. org; https: // orcid. org / 0000 - 0001 - 6560 - 6933 si.he@mobot.org text Phytotaxa 2021 2021-09-21 520 3 279 284 http://dx.doi.org/10.11646/phytotaxa.520.3.7 journal article 10.11646/phytotaxa.520.3.7 1179-3163 5530418 Key to the species of the Rhachitheciaceae in Thailand 1. Leaves usually less than 1 mm , chlorophyllose laminal cells papillose, costa ending just below leaf apex. Seta strongly spiraling; peristome teeth with palisade-like markings on both surfaces................................................................. Hypnodontopsis spathulata 1. Leaves usually longer than 1 mm long, chlorophyllose laminal cells smooth, costa 4/5–6/7 the leaf length. Seta somewhat straight; peristome teeth without palisade-like markings ....................................................................................... Rhachithecium perpusillum