Leaflet epidermal studies and taxonomic significance of trichomes in the Rubus subgenus Rubus (Rosaceae) in Iran

This study was to explore the foliar epidermis and trichome diversity of seven Rubus species, including R. caesius, R. discolor, R. dolichocarpus, R. hirtus, R. hyrcanus, R. persicus, and R. sanctus. The results showed that polygonal cells with straight to curved walls occurred in R. caesius of the treated species. Irregular cells with anticlinal straight to curved walls were also observed in R. sanctus and R. discolor. Sinuous cells were found in the epidermis. Irregular cells with straight to curved anticlinal walls were discovered on the abaxial side of leaves of R. caesius and R. sanctus. Sinuous cells with undulating walls were observed in the other examined species. No stomata were present on the adaxial leaf sides of the examined species, except in R. hirtus. An anemocytic stomata type was observed on the adaxial leaf sides of the studied species. Indumentums were studied and five types of covering trichomes were found: namely, covering trichome, stellate hairs, simple trichome, dentate, trifid branchy, and branchystalk trichome. Furthermore, three types of glandular trichomes were present too.