Chatan & Promprom: A New Species of Zingiberaceae From Thailand.

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 , such as red or pinkish-red leaf sheaths, leaf blades (1.

Ardisiacrenatasubsp.mukdahanensis, a new subspecies of Primulaceae from Thailand.

A new subspecies, ArdisiacrenataSimssubsp.mukdahanensis Chatan & Promprom (Primulaceae), is described from Mukdahan Province, Thailand. This discovery was made during field studies conducted from 2021 to 2023, during which the authors collected and analysed specimens, comparing them with relevant taxonomic literature and herbarium collections.

(Araceae), a new species from northeastern Thailand.

Chatan & Promprom (Araceae), a new species from northeastern Thailand, is described and illustrated. It is clearly different from other previously known species by leaves, spathe, ovary, sterile interstice, synandria, and appendix. Color illustrations, and a distribution map are provided, as well as comparative morphological characters about its similar species.

A new species of (Araceae) from northeastern Thailand.

Chatan & Promprom, a new species from northeastern Thailand, is described and illustrated. The new species is most similar to Engl. & Gehrm.

A new species of (Apocynaceae, Asclepiadoideae) from North-eastern Thailand.

Chatan & Promprom, a new species from north-eastern Thailand, is described and illustrated. The new species is similar to Costantin, but is distinguished by the shape of its leaves, the apices of the staminal corona lobes, the colour of the corolla and the absence of a corolline corona. The distinguishing characters of similar species are discussed.

(Detarioideae, Leguminosae), a new species from Thailand.

, a new species in the subfamily Detarioideae (Leguminosae), collected from Nakhon Phanom Province, Thailand, is described and illustrated. The new species is morphologically similar to but differs in its smaller stature (3-5 m high), 6-foliolate paripinnate leaves, falcate persistent stipules, presence of a petal auricle, absence of a petal claw, stipitate ovary and capitate stigma. A key to the Thailand and Malesia species of is provided.

A new species of Bauhinia L. (Caesalpinioideae, Leguminosae) from Nakhon Phanom Province, Thailand.

A new liana species of the subfamily Caesalpinioideae (Leguminosae), namely Bauhinia nakhonphanomensis, collected from the Phulangkha National Park, Nakhon Pranom Province, Thailand, is described and illustrated. It is easily recognized by the following combination of characters: tendrilled liana, entire leaves, acuminate or caudate leaf apices, oblong or elliptic floral bud, floral bud 25-35 mm long, raceme or panicle inflorescence, 10-13 mm long hypanthium, anther opening by longitudinal slits. Important comparative morphological characters with some closely related species are discussed.