A species of Thai Ilex (Aquifoliaceae), I. inthanonensis, is reported new to science. Ilex inthanonensis is glabrous on most parts except puberulent in the infructescences, leaf blade punctate below, fruiting pedicels shorter than or equalling fruit diameter, calyx 4–5-lobed, pyrenes 4–5 with 3–5(–6)-striae slightly elevated dorsally, not sulcate and laterally smooth. A morphological description is provided, just like photos and a line drawing. The new species is critically compared the most resembling species.

Five Begonia species are recorded from Cambodia of which Begonia longifolia is reported for Cambodia for the first time. An updated checklist of Begonia with sectional classification, and species expected to occur in Cambodia are also provided, supplemented with photographs, information on geographical range and a distribution map showing occurrences in Cambodia.

Phanera godefroyi, previously only known from Cambodia, is recorded for Thailand. A full description of Phanera godefroyi is provided for the first time, based on fresh specimens with flowers and fruits, accompanied by colour photographs to assist identification, added are notes on its ecology, phenology, and taxonomy. Evidence from nuclear (ITS) and chloroplast data (trnK/matK, the trnL intron and trnL–F spacer) in our phylogenetic study suggests that the species is sister to P. curtisii and P. scandens. In addition, pollen morphology examined with Light and Scanning Electron Microscopes supports the recognition of the species by its typical combination of palynological characters, like the prolate spheroidal shape, colpi with granules, a distinctly thickened annulus around the endoaperture areas, and a rugulate ornamentation of the exine.

A species of Meliaceae, Aglaia bracteolata is newly added to the flora of Thailand. It was first recognized in Suan Hin Pha Ngam Forest Park, Loei Province, and is described and illustrated here. This species is found on the limestone hill, characterized by the presence of Cycas petraea and Dracaena cambodiana. It is also found in Phayao, Lampang and Kanchanaburi Provinces.

Three species of Curcuma subgen. Ecomatae, Curcuma bicolor, C. nakhonphanomensis, and C. rubroaurantiaca, are newly recorded for the flora of Laos. Descriptions and colour plates, as well as notes on ecology and phenology, are provided for all three species. In addition, a key to species of Curcuma subgen. Ecomatae in Laos is also provided.

Mappianthus kachinensis, a new species currently only known from Kachin State, Putao District, northern Myanmar, is described and illustrated. A detailed description along with etymology, conservation status, and a line illustration are provided for a new species. The genus is still poorly known, and this discovery increases the number of species in Mappianthus to at least three. Problems with species delimitation in the genus are also briefly discussed.

Paraboea verticillata, previously only known from Peninsular Malaysia, has been found on a limestone outcrop in Yala Province, Southern Thailand. The species is described and illustrated here.

Eleven species of Strobilanthes (Acanthaceae) are recorded from the Bolaven Plateau in southern Laos. A key to the species, photographs, vernacular names, taxonomic notes and information on distributions, habitat and phenology, are provided. In addition, two species (S. dalzielii and S. glaucescens) are lectotypified.

A taxonomic account of the genus Pitardella in Thailand, with P. poilanei the sole species, is presented. Description, photographs and taxonomic notes are provided based on newly collected materials; in addition, a lectotype for P. poilanei is designated.

Diplospora siamica is newly recorded for the flora of Vietnam. It was found in Muong La Nature Reserve, Son La Province, northern Vietnam. A description and colour photos of the species are provided. A key to Diplospora species in Vietnam is also given.