Comparative study of upper and lower leaf epidermis and trichomes in some species belong to Malvaceae family

: Leaf characteristics of four genera represented by nine species belonging to the family Malvaceae were examined: Althaea ludwigii L., Gossypium herbaceum L., Hibiscus cannabinum L., H. sabdariffa L., H. rosa-sinensis L., H. tiliaceus L., Malva sylvestris L., M. nicaeensis All., and M. parviflora L. The results reveal differences in the shape of anticlinal wall cells, stomatal frequency, stomatal index, and trichome types among the species. Additionally, the shape of the anticlinal wall cells is straight in A. ludwigii, G. herbaceum, H. sabdariffa and H. tiliaceu species; sinuate in H. cannabinum and H. rosa-sinensis and undulate or strongly undulate in Malva species. On average epidermal cells in the upper epidermis of M. sylvestris were 91.25 µm long, while on average, they were 27.18 µm long in H. tiliaceus. The current results identified five different stomatal patterns: anomocytic (rununculaceous); hemiparacytic; paracytic; anisocytic (cruciferous) and diacytic. Trichomes on the leaves are recognized as unicellular non-glandular in M. parviflora, M. nicaeensis, and M. sylvestris, glandular in H. rosa-sinensis, G. herbaceum, and H. sabdariffa, and stellate hairs in M. nicaeensis, M. parviflora, M. sylvestris and A. ludwigii. The stomatal index varies between species and on the upper and lower epidermis. The highest stomatal index was 50.98 in H. sabdariffa on the lower surface and the lowest 7.11 on the upper surface.