Glandular and Eglandular Trichomes of Endemic Ballota glandulosissima (Lamiaceae)

Abstract

The aim of this study is to determine the taxonomic importance of the glandular and eglandular trichomes on the vegetative and reproductive organs of Ballota glandulosissima. This species is endemic to Türkiye and the Eastern Mediterranean element. It is among the medicinal plants of Türkiye. On the vegetative and reproductive organs of the studied species, both glandular and eglandular trichomes were seen. These trichomes were examined using light and stereo microscopes. The glandular trichomes were divided into peltate and capitate. The eglandular trichomes were grouped as branched (stellate, bicellular, and multicellular) and unbranched (simple unbranched eglandular trichomes). The stalk cell number of capitate glandular trichomes shows changes. According to the number of stalk cells, capitate glandular trichomes were grouped into uni, bi, tri, and multi-cellular trichomes. In the taxon, dendroid trichomes were not observed on the vegetative and reproductive organs. The stellate trichomes were dense on the upper and lower surfaces of the leaf, and calyx teeth, while capitate glandular trichomes were dense on the petiole, stem, leaf, and outside part of the calyx, and calyx teeth. Peltate glandular trichomes are dense on the calyx and corolla. Especially, the capitate glandular and stellate trichomes are found to have significant taxonomic characteristics in distinguishing this species.