https://li01.tci-thaijo.org/index.php/ThaiForestBulletin <p>Thai Forest Bulletin (Botany) - here referred to as TFB (Botany) - was first published in 1954 by the Royal Forest Department, under the leadership of its first editor Prof. Dr. Tem Smitinand. In 2002, the journal was published by the Department of National Parks, Wildlife and Plant Conservation with Prof. Dr. Thawatchai Santisuk as editor, supported by editorial board members from several prominent herbaria in Europe. At present, the TFB (Botany) is published by the Forest Herbarium in Bangkok, with Dr. Tim Utteridge and Ms Nannapat Pattharahirantricin as editors. The journal is published once a year, usually January with the manuscript no submission deadline, and articles are published in English. All manuscripts are peer reviewed by international scientists and edited by native English language speakers on the editorial board before acceptance and publication. TFB (Botany) will become both printed and electronic journal starting with volume 44 (2016), and through the TFB (Botany) Archive, every article published since 1954 is available and completely searchable online.</p> <p>ISSN : 0495-3843 (print), 2465-423x (electronic)</p> Forest Herbarium (BKF) en-US Thai Forest Bulletin (Botany) 0495-3843 https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/262160 <p>A taxonomic revision of <em>Mayodendron</em> (Bignoniaceae) in Thailand is presented. One species, <em>M. igneum</em>, is recognized and provided with an updated morphological description, comparison with related species, illustrations, distribution, habitat and ecological data, phenology, conservation assessment, vernacular names, uses, and a list of specimens examined. Based on the reproductive morphological characters, <em>Mayodendron</em> can be distinguished from <em>Radermachera</em> by the type and position of the inflorescences, the morphology of the calyx and corolla, and the size and characteristics of the fertile stamens. The specimen<em> Brandis 1357</em> at HBG [HBG522936] is designated as the lectotype of <em>M. igneum</em>. This species is assessed as Least Concern (LC) according to the IUCN criteria. Leaflet and wood anatomy, as well as pollen morphology of <em>M. igneum</em> are characterized. The species has bifacial leaflets with anomocytic stomata, diffuse-porous wood with hetero- or homocellular rays, and prolate-spheroidal to subprolate pollen with heterobrocate reticulate sculpturing and four aperture types.</p> Chatchai Ngernsaengsaruay Weereesa Boonthasak Voradol Chamchumroon Copyright (c) 2026 The Forest Herbarium http://creativecommons.org/licenses/by-nc-nd/4.0 2026-04-30 2026-04-30 54 1 41 57 10.20531/tfb.2026.54.1.05 https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/270132 <p>A comprehensive taxonomic revision of <em>Gnetum</em> (Gnetaceae) in Thailand is presented based on morphological characters. Eleven taxa are recognised (ten species and two varieties) including two newly described species, <em>Gnetum khaoluangense</em> and <em>G. megaspermum</em>, both endemic to Thailand. An update of morphological characters, taxon descriptions (including illustrations of the two new species), diagnostic characters, and an identification key to all Thai taxa, are provided. Lectotypification is provided for six taxa: <em>G. cuspidatum</em>, <em>G. gnemon</em> var. <em>tenerum</em>, <em>G. leptostachyum</em>, <em>G. macrostachyum</em>, <em>G. microcarpum</em> and<em> G. tenuifolium</em>.</p> Kesanee Kuaphu Somran Suddee Trevor Hodkinson Ruamporn Kongjan Chalermpol Suwanphakdee Copyright (c) 2026 The Forest Herbarium http://creativecommons.org/licenses/by-nc-nd/4.0 2026-03-24 2026-03-24 54 1 23 40 10.20531/tfb.2026.54.1.04 https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/266446 <p><em>Tetrastigma quangninhense</em> (Vitaceae), a new species found in Quang Ninh Province, northern Vietnam, referable to <em>Tetrastigma </em>sect. <em>Tetrastigma</em> is described. A morphological comparison with resembling species is provided. A description, details of distribution and habitat are supplemented with photos.</p> Nguyen The Cuong Minh Tam Ha Van Hai Do Pimwadee Pornpongrungrueng Copyright (c) 2026 The Forest Herbarium http://creativecommons.org/licenses/by-nc-nd/4.0 2026-03-06 2026-03-06 54 1 18 22 10.20531/tfb.2026.54.1.03 https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/259689 <p><em>Peliosanthes siamensis</em> (Asparagaceae) is described from northern Thailand. A description, distribution, ecology, phenology, notes and illustration are provided. A provisional conservation status of the species in Thailand is also given.</p> Woranart Thammarong Woranuch La-ongsri Wattana Tanming Sarayut Rakarcha Copyright (c) 2026 The Forest Herbarium http://creativecommons.org/licenses/by-nc-nd/4.0 2026-02-25 2026-02-25 54 1 13 17 10.20531/tfb.2026.54.1.02 https://li01.tci-thaijo.org/index.php/ThaiForestBulletin/article/view/265936 <p>Two new species,<em> Greenea laotica </em>(Rubiaceae) and<em> Palaquium laoticum </em>(Sapotaceae), are described based on specimens collected from the Nam Kading National Protected Area and its vicinity in central Laos. In addition, seven taxa of angiosperms are reported as new records for the flora of Laos: <em>Lonicera macrantha </em>(Caprifoliaceae)<em>, Heritiera angustata</em>,<em> Heritiera parvifolia </em>(Malvaceae), <em>Olax imbricata</em> (Olacaceae), <em>Pellacalyx yunnanensis </em>(Rhizophoraceae),<em> Psychotria bonii </em>(Rubiaceae), and<em> Pouzolzia zeylanica </em>var.<em> calcicola </em>(Urticaceae)<em>.</em> For each species, voucher specimens are cited, photographs are shown and additional information including geographical distribution, ecology and taxonomic notes are provided. Lectotype is proposed for <em>Olax imbricata</em>.</p> Shuichiro Tagane Phetlasy Souladeth Deuanta Kongxaisavath Keooudone Souvannakhoummane Phongphayboun Phonepaseuth Thyraphon Vongthavone Van Son Dang Takenori Yamamoto Copyright (c) 2026 The Forest Herbarium http://creativecommons.org/licenses/by-nc-nd/4.0 2026-01-06 2026-01-06 54 1 1 12 10.20531/tfb.2026.54.1.01