The indumentum of vegetative and reproductive parts of annual Silene L. species (Caryophyllaceae) in Iran

Large and diverse genera, such as Silene need more reliable morphological traits for the credible identification and delimitation of the species. Despite the fact that the type of indumentum among the species of Silene had been addressed in most available revisions, monographs and floristic studies, the trichome-based features and their adaptational importance have not been investigated explicitly. In the present study, the trichomes of annual species of Silene in Iran are studied. Beside other floral traits and vegetative features, the presence, distribution and mixture of the glandular and eglandular trichomes on stems, leaves, inflorescence axes, pedicels, anthophores, inner and outer surfaces of calyces, petals and styles are proved to be of diagnostic importance in Silene. Indumentum of the inner calyx among the studied species is investigated here for the first time. An identification key is performed mainly based on indumentum features. In addition, a putative trichome-based defense strategy is proposed in the examined species.