The pitviper species Trimeresurus caudornatus was recently described based on only two specimens from Nabang Town, Yingjiang County, Yunnan Province, China. Here, we provide additional data on this species based on a re-examination of 19 preserved specimens, 16 specimens reported in earlier literature sources, and additional photo-documented records from northern Myanmar (Burma) and adjacent China. All new specimens were previously identified as Trimeresurus albolabris sensu lato or Trimeresurus septentrionalis sensu lato. Molecular analyses based on mitochondrial DNA supported the morphological findings in establishing conspecificity with T. caudornatus. The newly identified specimens have a pairwise distance of only 0.4–2.6% from those of the type series of T. caudornatus (based on the cytochrome b gene). Based on these findings, we confirm the presence of T. caudornatus from Myanmar and update its diagnostic characters and distribution. We suggest the species should be considered as Least Concern (LC) following the IUCN’s Red List categories. Further studies reassessing the populations of the Trimeresurus albolabris complex are required.

Limestone habitats in Southeast Asia often harbour narrowly distributed plant diversity, and several limestone-associated taxa of Boesenbergia require further taxonomic documentation. Field surveys and ex situ observations of living material from Loei Province, northeastern Thailand, revealed a distinctive Boesenbergia population associated with shaded limestone microhabitats. This study evaluates this population using comparative morphology, herbarium and literature comparisons, phenetic analyses based on 25 selected morphological characters, and a preliminary conservation assessment. Boesenbergia lamudiae Boonma, Saensouk & P.Saensouk, sp. nov., is described and illustrated. The species is morphologically most similar to B. burmanica Boonma, P.Saensouk & Saensouk, and resembles B. rotunda sensu lato in having a terminal inflorescence enclosed within the leaf sheaths and lacking an androecial cup. It differs by its broadly elliptic to ovate-elliptic laminae with an arachnoid abaxial surface, maroon lanceolate bracts, longer pubescent calyx with an acute to acuminate apex, non-saccate obovate labellum with a sharply delimited maroon transverse colour zone, larger anther crest, longer epigynous glands, and pubescent ovary. Principal coordinates analysis (PCoA) and unweighted pair group method with arithmetic mean (UPGMA) clustering based on Gower distance separated B. lamudiae from all compared operational units, supporting its morphological distinctiveness. The species is currently known only from Nong Hin District and is provisionally assessed as Critically Endangered (CR) under criterion D.

Boesenbergia burmanica Boonma, P.Saensouk & Saensouk, a new species from Naypyidaw Union Territory, Myanmar, is described based on morphological examination of specimens collected during field surveys in 2024–2025. The genus Boesenbergia is taxonomically complex, and ongoing botanical exploration in Southeast Asia continues to reveal undescribed taxa. Comparative analyses of living plants, herbarium materials, and published descriptions were conducted to determine diagnostic features. Boesenbergia burmanica is closely related to B. meghalayensis Aishwarya & M.Sabu but differs in having ovoid, branched rhizomes, a pubescent lamina on both surfaces, and an oblanceolate labellum with bright red markings. It grows in shady, sandy-loam habitats at 140–145 m elevation and flowers from August to September, producing inflorescences with nine to ten flowers. Species of Boesenbergia are traditionally used in Myanmar and neighboring regions as medicinal and ornamental plants, and notes on local ethnobotanical knowledge are provided. The new species exhibits high ornamental potential due to its compact clumping habit and attractive floral coloration. Cultivation guidelines are provided to support ex situ conservation and horticultural development for sustainable use. This discovery increases the number of Boesenbergia species recorded in Myanmar to 14 and highlights the importance of continued field-based taxonomic and conservation research on regional Zingiberaceae diversity.

This study documents the diversity, ethnobotany, and ethnolinguistic aspects of Passifloraceae species in Non Din Daeng District, Buri Ram Province, Thailand. Field surveys conducted from April 2024 to March 2025 recorded nine taxa across three genera, including two native species (Adenia heterophylla and A. viridiflora) newly reported for Buri Ram Province, and seven taxa (Passiflora ‘Soi Fah’, P. edulis f. flavicarpa, P. miniata, P. trifasciata, P. vesicaria, Turnera subulata, and T. ulmifolia) representing new provincial records. Native species were primarily associated with dry dipterocarp and mixed deciduous forests, whereas introduced taxa occurred mainly in cultivated or disturbed habitats, reflecting both ecological adaptability and human-mediated introduction. Ethnobotanical data revealed diverse uses including food, traditional medicine, ornamentals, beverages, and economic purposes with P. edulis f. flavicarpa and A. viridiflora having particularly high cultural and economic significance. Passiflora flower also holds cultural prominence, inspiring local and iconic textile motifs of Non Din Daeng. Vernacular names and terminology provide insights into local classification systems and cultural perceptions of these plants. Conservation assessments indicate potential threats to A. heterophylla from wild harvesting, whereas cultivated and naturalized Passiflora taxa are assessed as Least Concern. The results highlight the ecological, cultural, and economic value of Passifloraceae in Non Din Daeng District and emphasize the role of community knowledge in biodiversity conservation and sustainable management.

The taxonomy and distribution of Kaempferia subgen. Protanthium (Zingiberaceae) in Myanmar remain incompletely documented despite the botanical significance of the region. This study aims to clarify the diversity and taxonomic status of species belonging to this subgenus in Myanmar through field investigations and herbarium studies. Detailed morphological examinations of newly collected and previously documented specimens were conducted to evaluate diagnostic characters and species delimitation. As a result, Kaempferia kayinensis is described in this paper as a new species from Kayin State, southeastern Myanmar, and K. simaoensis Y.Y.Qian as a new country record. In addition, the taxonomic status of K. parishii Hook.f. is reassessed and reinstated based on morphological evidence, distinguishing it from K. ovalifolia Roxb. These findings confirm the presence of four species of Kaempferia subgen. Protanthium in Myanmar (K. kayinensis, K. parishii, K. rotunda, and K. simaoensis) and increase the number of known Kaempferia species in the country to twelve. The results highlight the importance of continued floristic and taxonomic studies to better document the diversity of Kaempferia in Myanmar.

Curcuma subgen. Ecomatae comprises several morphologically similar taxa whose delimitation requires careful evaluation of character combinations and intraspecific variation. Botanical surveys across Southwestern Thailand revealed six geographically separated populations of an unidentified Curcuma in Uthai Thani, Kanchanaburi, Ratchaburi, Phetchaburi, and Prachuap Khiri Khan provinces. Taxonomic status was evaluated through detailed comparative morphology and complementary individual-level phenetic analyses of 42 morphological characters using Gower distances, UPGMA clustering, and principal coordinates analysis (PCoA). The analyses comprised a population-level assessment of 120 individuals from six populations and an interspecific comparison of 200 individuals, including the same 120 individuals of the putative new taxon and 20 individuals each of four morphologically allied species. The populations are recognized here as a distinct species, Curcuma tenasserimensis Boonma, Saensouk & P.Saensouk, sp. nov., based on a consistent combination of vegetative, inflorescence, floral, and reproductive characters that distinguishes them from the morphologically allied species examined. The population-level analysis revealed morphological variation among the six geographically separated populations while retaining their overall morphological cohesion. In the interspecific analysis, individuals of C. tenasserimensis formed an overall morphologically cohesive assemblage that was differentiated from the four allied species examined. Together, comparative morphology and individual-level phenetic analyses are consistent with the recognition of C. tenasserimensis as a morphologically distinct species and further document the still-emerging diversity of subgen. Ecomatae in Southwestern Thailand.