Essential oil contents and micromorphological traits of Stachys iva Griseb. and S. horvaticii Micevski (Lamiaceae)

Chemical composition of the essential oil (EO) (analysed by GC and GC-MS), the types and distribution of trichomes, and pollen morphology were investigated in Stachys iva Griseb. and S. horvaticii Micevski (Lamiaceae) growing in Republic of Macedonia. The essential oil of Stachys iva was characterized by a high concentration of oxygenated sesquiterpene (43.8%) of which caryophyllene oxide (34.2%) and spathulenol (8.3%) being the principal compounds, while hexadecanoic acid being a major component in the both S. horvaticii oil with percentages of 25.7% in the oil from locality Babuna River Gorge and 28.4 % in the oil from locality Rajec River Gorge. Non-glandular trichomes, and two type of capitate trichomes (type 1 composed of one basal epidermal cell, one stem cell and a unicellular head cell with subcuticular space ; type 2 composed of one elevated basal epidermal cell, one stem cells, and a head composed of four, sometimes two small cells) were observed on leaves, calyx and the stem.