Diversity of Foliar Trichomes and Their Systematic Relevance in the Genus Hibiscus (Malvaceae)

Qualitative and quantitative micromorphological characters, distribution and systematic relevance of both glandular and eglandular foliar trichomes in species of genus Hibiscus (Malvaceae) including H. caesius, H. mutabilis, H. rosa-sinensis, H. sabdariffa, H. schizopetalus, H. syriacus and H. trionum were characterized. Diversity of these epidermal appendages were separated into eight main types. Glandular capitate trichomes were the most abundant on both leaf surfaces of all the examined taxa. H. mutabilis was discrete in having multicellular uniseriate columna as a prominent feature of its abaxial leaf surface, whereas H. schizopetalus and H. sabdariffa could be demarked due to the twisted or Spirogyra-like appearance of their eglandular trichomes. In summary, the variation in morphology and distribution of foliar trichomes emerged as an important supportive taxonomic tool in delimiting species of genus Hibiscus.