Wannachai Chatan

Botanical exploration of northeastern Thailand has revealed substantial undocumented diversity within Typhonium (Araceae). Here, T. boonkerdii Chatan & Promprom is described and illustrated as a new geophytic species from Mukdahan Province. The taxonomic treatment is based on study of living plants during vegetative, flowering, and fruiting stages, together with comparative examination of herbarium specimens and relevant taxonomic literature. Typhonium boonkerdii is morphologically most similar to T. cucullatum but is distinguished by its shortly acute to shortly acuminate leaf-blade apex, longer and broader pistillate zone comprising 4–5 rows of densely congested pistils, larger ovaries and stigmas, broader sterile interstice, and mutually distant staminodes with downward- to slightly downward-directed apices. The new species further differs in having a longer staminate zone with 6–7 whorls of stamens, an appendix with an abruptly but slightly expanded base, and a longer stipe. Although both species show a similar sequence of spathe-limb movement during anthesis, the consistent combination of characters clearly supports the recognition of T. boonkerdii as a distinct species. The species is currently known from a single population in mixed deciduous forest at 300–400 m elevation. As the total population is estimated to comprise fewer than 50 mature individuals, the species is provisionally assessed as Critically Endangered (CR) following the IUCN Red List Categories and Criteria. A detailed description, photographic illustrations, distribution map, morphological comparison, and identification key are provided.

Typhonium is one of the most species-rich genera of Araceae in tropical Asia, with north-eastern Thailand representing an important but still incompletely documented area of diversity. During botanical surveys in northeastern Thailand, an unusual population of Typhonium was discovered in mixed deciduous forest and dry evergreen forest at 300–400 m elevation. Detailed morphological study of living plants and herbarium specimens, together with comparisons with relevant protologues, regional floras, and recently described species, confirmed that this population represents a species new to science. It is here described as Typhonium mukdahanense Chatan & Promprom, sp. nov. The new species is morphologically most similar to T. fornicatum, but differs by its taller habit, larger hastate to trisect leaf blades, more numerous primary lateral veins, larger and nearly symmetrical spathe tube, triangular reflexed spathe limb, dark red stigma with a cream-colored depressed center, sterile interstice bearing 10–14 staminodes arranged in two whorls, slightly curved and not spreading–declinate appendix, and pyriform mottled berries. It also differs from T. acetosella by its broader leaf blades, reflexed triangular spathe limb, dark red stigma, and pyriform fruits. The new species is currently known only from the type locality and is therefore provisionally assessed as Critically Endangered (CR) according to the IUCN Red List Categories and Criteria. A detailed description, diagnosis, information on distribution, habitat, phenology, conservation status, and an identification key to morphologically similar species are provided.

Pycnospatha is a small and poorly known genus of Araceae distributed in Indochina and currently comprising only two accepted species. During botanical surveys in Si Sa Ket Province, eastern Thailand, an unusual population of Pycnospatha was discovered in a dry dipterocarp forest and found to differ from both P. arietina and P. palmata. Here, we describe this plant as a new species, Pycnospatha phanomdongrakensis. The new species is distinguished by a combination of characters, including a slender habit, shorter petiole and peduncle, a medium-sized spathe, a short and dense spadix, a distinctly curved style directed toward the apex of the spadix, a geophilous and ovoid infructescence, obovate berries, and asymmetrically ovoid seeds. The new taxon is currently known only from a single population in the Phanom Dong Rak mountain range. A preliminary conservation assessment is provided, and the species is treated as Critically Endangered (CR) following IUCN guidelines. An identification key to all species of Pycnospatha is also presented. The discovery of this new species highlights the continuing importance of field-based taxonomy in revealing overlooked aroid diversity in the seasonally dry forests of eastern Thailand.

Neuroinflammation is pivotal in the development of numerous neurodegenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). Microglial cells, the principal immune cells of the central nervous system (CNS), are essential mediators of this process. Upon exposure to pathogenic stimuli such as lipopolysaccharide (LPS), microglia activate and release pro-inflammatory mediators, leading to heightened oxidative stress and neuronal damage. Therefore, targeting microglial activation is a promising therapeutic approach to prevent or slow neurodegeneration. This study aimed to investigate the antioxidant and anti-inflammatory effects of the leaf extract of the newly identified species Bauhinia thailandica on LPS-activated BV2 microglia. The phytochemical compound of the B. thailandica leaf extract was also investigated. BV2 cells were treated with LPS (1 μg/mL) for 24 h in the presence or absence of B. thailandica leaf extract (12.5 and 25 µg/mL). The levels of reactive oxygen species (ROS), nitric oxide (NO), and interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-alpha (TNF-α) were quantified with CM-H2DCFDA, Griess reagent assay, and ELISA, respectively. Treatment with LPS resulted in significant increases in ROS, NO, IL-6, IL-1, and TNF levels compared to untreated cells (p < 0.01). However, co-treatment with B. thailandica leaf extract significantly suppressed the production of these inflammatory markers (p < 0.01 for 25 µg/mL across all parameters, except TNF-α; p < 0.05). The results also showed that B. thailandica leaf extract possessed significant levels of total phenolic content (TPC; 70.55 mg GAE/g dry extract), total flavonoid content (TFC; 249.47 mg QE/g dry extract), and tannins (397.50 mg TAE/g dry extract). Phytochemical screening also revealed the presence of saponins and cardiac glycosides in the extract. In conclusion, the leaf extract of B. thailandica is a potent source of phytochemicals exhibiting antioxidant capabilities and has shown both antioxidant and anti-inflammatory actions in LPS-activated BV2 microglial cells. The findings indicate that B. thailandica leaf extract shows significant promise as a novel herbal treatment for neuroinflammatory disorders mediated by microglia. Further research is necessary to clarify the underlying mechanisms of action and to investigate the active substances responsible for these effects.

Colocasia sookchaloemiae (Araceae) is described from Phu Pha Yol National Park (northeastern Thailand). It is morphologically similar to C. fallax , from which it differs in having seasonal dormancy (vs. evergreen), broader and non-glaucous laminae (vs. narrower and slightly glaucous beneath), a speckled green ovary (vs. mostly green), a convex stigma with a depressed center (vs. 3-lobed), a sparsely hairy sterile interstice (vs. glabrous), and a thicker stipitate appendix (vs. slender, often sessile, or shortly stipitate). A comparative study of living plants, cultivated specimens, and herbarium material (including types) supports its recognition as a distinct species. The new taxon grows on rocky cliffs in dry dipterocarp and mixed deciduous forests at 350–400 m a.s.l., and it is currently known from Mukdahan and Sakon Nakhon provinces. A preliminary IUCN assessment indicates that the species is Data Deficient (DD).

This study investigated the phytochemical composition, antioxidant capacity, and anti‐inflammatory potential of ethanolic leaf extracts of Piliostigma malabaricum and Cheniella lakhonensis . Preliminary phytochemical screening showed that both species contained phenolic compounds, flavonoids, tannins, saponins, and cardiac glycosides, indicating diverse secondary metabolites. Quantitative analysis showed that C. lakhonensis contained higher total phenolic, flavonoid, and tannin contents than P. malabaricum . The antioxidant activity of the extracts was assessed using the DPPH radical‐scavenging assay and was significantly stronger in C. lakhonensis (IC ₅₀ = 132.77 ± 3.80 μg/mL) than in P. malabaricum (IC ₅₀ = 322.96 ± 2.77 μg/mL), compared with ascorbic acid (IC ₅₀ = 68.25 ± 2.30 μg/mL). Both extracts demonstrated significant suppression of albumin denaturation under the evaluated in vitro conditions, indicating initial anti‐inflammatory capabilities, with P. malabaricum showing a slightly higher inhibitory effect. HPLC quantification and LC‐MS analysis investigations verified the existence of quercetin and quercitrin in both species, with elevated concentrations observed in C . lakhonensis . These results offer initial in vitro evidence suggesting that both species could be valuable sources of bioactive compounds; nonetheless, further antioxidant assays, mechanistic research, safety assessments, and in vivo studies are necessary prior to confirming their functional food or therapeutic uses.

Camchaya khongchiamensis Chatan & Promprom (Asteraceae), a new species from Ubon Ratchathani Province, Thailand, is described and illustrated. It is similar to C. loloana, but clearly different from C. loloana by having a larger size of capitula, involucre, receptacle, and corolla lobe. In addition, it mostly has fewer florets (18–40 [−50]) per capitulum; lower haft whitish, upper haft purplish corolla tubes; sagittate base anthers; and white except for the purple near apex style. A distribution map, pollen morphology, and a table with comparative morphological characters of the new species and its closest relative are provided, as well as the preliminary conservation assessment under the IUCN criteria.

Solanum baumii Chatan and Promprom, a new species from Mukdahan Province, Phu Pha Yol National Park, northeastern Thailand, is morphologically described and illustrated. It is similar to Solanum barbisetum Nees and Solanum praetermissum Kerr ex Barnett, but it clearly differs from two latter species in several ways. Its young stems are armed with very few and thin prickles, which become unarmed as they age, with brownish‐green prickles in live plants. The flowers are 4–5‐merous, and the calyx tube is 5.0–5.5 mm long with brownish‐green prickles, while the corolla is always white. The androecium consists of 4–5 stamens. The ovaries are glabrous except for sparsely glandular hairs near the apex, and the fruits are 1.0–1.2 cm in diameter, green at maturity. A key to these closely related species is presented. The preliminary conservation status was assessed, and the distinct morphological characters between the new and similar species were discussed.

Fisheries and Aquatic Sciences

Zingiber baumii Chatan & Promprom, a new species from the Zingiberaceae family, is described from Sakon Nakhon Province in northeastern Thailand. This species was identified during field expeditions conducted between 2018 and 2024 in Phu Pha Yol National Park. The morphological characteristics of Z. baumii, such as red or pinkish‐red leaf sheaths, leaf blades (1.5−) 2.0–3.0 cm wide, pink petioles, and bright yellow corolla with a red patch, distinguish it from closely related species such as Z. isanense Triboun & K. Larsen. Zingiber baumii grows in slightly shaded dry dipterocarp forests at elevations of 300–380 m. The preliminary conservation assessment indicates that this species should be classified as Endangered (EN) according to IUCN criteria due to its limited distribution and small population size. Detailed morphological comparisons with related species are provided, along with illustrations and habitat descriptions.