A morphological survey of foliar trichomes of Croton L. (Euphorbiaceae) in Thailand

Abstract

The morphology of foliar trichomes of 23 species of Croton in Thailand was studied by scanning electron microscopy and by light microscopy. Seven main trichome types characterized by their morphology were found, namely, stellate, fasciculate, multiradiate-rosulate, dendritic, lepidote, glandular and simple types. Some trichome subtypes are useful for species identifi cation, particularly stellate rotate trichomes with a central porrect ray are found only in C. tiglium, appressed stellate trichomes in C. griffi thii and glandular trichomes are restricted to C. caudatus, C. crassifolius and C. hirtus.