Glandular trichomes of S. argentea
Glandular trichomes are widely distributed on the aerial 
parts of Lamiaceae.Peeled trichomes are present on all aerial organs except 
the petiole and are more abundant on the calyx and the 
corolla.19
The essential oil produced by the glandular trichomes is 
one of the characteristic traits of the Lamiaceae family.20
Glandular trichomes that develop from epidermal cells are 
generally considered to be the site of biosynthesis or 
accumulation of essential oils.21,22
Essential oil produced by the glandular trichomes of the 
Lamiaceae family is important for the pharmaceutical and 
cosmetic industry, and its valorization as a bio-pesticide is 
very promising.16,23 This oil, which gives a special 
fragrance, is characteristic of many species of the genus 
Salvia.They are the main secreting organs of 
these plants, and their structures can vary considerably 
from one species to another.16
The glandular trichomes of S. argentea have been studied 
morphologically and anatomically and their distribution 
on aerial organs have been described.Two main types of 
morphologically distinct glandular trichomes were 
determined according to the classification of Werker et 
al.17 and Ozdemir and Senel18: 
1- Trichomes forming a base consisting of 1 to 7 cells with 
a stem of 1 to 5 cells; they can be stemless and have a uni-
or bi-cellular head with different shapes.It has been 
shown that the neck cell plays an important role, 
particularly in xeromorphic plants, acting to prevent the 
reflux of the secreted substances through the apoplast.2- Glandular trichomes with a large secretory head that 
may contain 5 to 8 central cells and 8 to 14 peripheral cells.24 The latter has the richest and most diversified 
glandular trichomes of the family.25