LEAF ANATOMICAL STUDY OF GYPSOPHILA (CARYOPHYLLACEAE) an‎d ALLIED GENERA IN IRAN an‎d ITS TAXONOMICAL IMPLICATION

Aanatomical features as revealed from cross-sections of leaf blades and midribs in 21 taxa of Gypsophila representing its currently recognized seven sections distributed in Iran as well as four species of Saponaria, two species of Allochrusa and one species of Ankyropetalum as its closely related genera are examined. In total nine quantitative and five qualitative characters were selected and measured. The most important characters include general shape of leaves (assessed only for narrow leaves) in transverse section, type of mesophyll (dorsi-ventral vs. isobilateral), thickness of sclerenchyma surrounding the vascular bundles, shape of central vascular bundle, number of parenchyma layers in midrib, thickness (number of layers) and structure of mesophyll, density and distribution of druses. In general, leaf anatomy does not provide any unique feature supporting the separation of genera Ankyropetalum and Allochrusa from Gypsophila. The number of spongy layers provides support at least for separation of Gypsophila (more than two layers) from most species of Saponaria (only one layer). Our results show that leaf anatomical features provide reliable evidence for subgeneric classification of Gypsophila and could be taxonomically valuable.