Micromorphology and histochemistry of trichomes of endemic nepeta rtanjensis (lamiaceae)

Abstract

Micromorphological and anatomical analyses of the indumentum of Nepeta rtanjensis, a Serbian/local endemic species, were performed by means of light and electron microscopy and described in detail. The leaves and stems bear numerous glandular trichomes, both peltate and capitate, as well as non-glandular unbranched trichomes. A basal epidermal cell, a short stalk cell and a large round head of four secretory cells constitute one peltate trichome. Capitate trichomes are short and long-stalked and can be divided into two types, based on the number of glandular head cells, and further into a few subtypes according to the length and number of cells in stalk. Capitate trichomes of smaller length with one-cellular or with a bicellular head have been previously reported in different Nepeta species; however, according to our best knowledge, no existing study has reported the presence of long capitate trichomes on vegetative organs in any other species of this genus.