Seed Morphological and Anatomical Structures as Taxonomy Tool for Turkish Hyacinthella Schur (Asparagaceae) Taxa

Abstract

This paper offers the first taxonomic assessment of the morphological and anatomical characters of the seeds of 11 Hyacinthella taxa from Turkey, ten of them are endemic, with the cluster analysis and principal component analysis. Macro-morphologically, all studied species can be differentiated from each other by the seed characters such as shape, size and surface ornamentation. The studied seeds are separated into 5 shapes; triangularis, circularis, ellipticus, ellipticus-late and ovatus. Seed size ranges from 1.51 mm to 3.06 mm in length and from 1.06 mm to 2.04 mm in width. Micro-morphologically, seed surface ornamentation is grouped into 7 types: rugose, reticulate-pusticulate, verrucate, tuberculate, ruminate, reticulate-foveate and alveolate. Anatomically, testa structures of the studied seeds are usually consisted of single layer, the epidermis, formed in the sclerenchymatous tissue. The epidermis layer demonstrates significant differences in cell form, comprising of crushed, flat or polygonal cells, in 1–7 layers, and has surged or straight wall form. The thickness of testa layers varies between 15.77 μm (in H. micrantha) and 49.76 μm (in H. campanulata). In the systematics of the genus Hyacinthella, the seed morphological and anatomical characters are very important characteristics that reveal inter-specific relationships among the studied species. Also, a dichotomous key is provided for the identification of the examined species based on seed characters.