Sideritis syriaca ssp. syriaca is a taxon with a low essential oil content. Its leaves bear glandular trichomes of two types: long hairs with a 4‐celled head, a 4‐celled stalk and a 4‐celled foot (reported for the first time in Lamiaceae) and short hairs with a 4–celled head, a unicellular stalk and a unicellular foot. The second type is considered intermediate between the capitate and peltate hairs, common in Lamiaceae, but found in S. syriaca ssp. syriaca. The ontogeny of the trichome types is described. The possible significance of the glandular trichome structure to Lamiaceae systematics is further di