Kanjana Pramali, a
Pogostemon section Eusteralis is comprised of diverse taxa found in a range of habitats, from terrestrial to aquatic/marshland. Hence, leaf micromorphological characters of the section Eusteralis in Thailand were investigated to assess the relationships between leaf micromorphological characters and environmental conditions and to explore alternative taxonomic characters for supporting the infrageneric classification. It was suggested that the major factor causing different leaf micromorphology in the section was water availability. Moreover, the important leaf micromorphological trait of Eusteralis that can distinguish this section from the section Pogostemon is the type of non-glandular trichomes