Two new morphometric parameters proposed to classify CRENATE-phytoliths of the Pooideae Benth.

The article proposes two additional morphometric parameters (L1 and L2) for classifying Crenate phytoliths of grass leaves into two submorphotypes: Crenate_lobate (CRE_LOB) and Crenate_sinuate (CRE_SIN). L1 characterizes the size of the lobe (wave), and L2 − the degree of its expression. Both morphometric parameters are calculated based on width and inscribed radius characteristics. The study examined 12 species of grasses belonging to three tribes (Poeae, Meliceae and Triticeae). Six species of grasses predominantly have CRE_LOB phytoliths, while the other six have CRE_SIN. Statistical data analysis revealed differences in the phytoliths of the Meliceae tribe based on classical morphometric characteristics (width and inscribed radius). The inscribed radius has similar values in the phytoliths of two closely related subtribes of Poeae (Agrostidinae, Aveninae). The two newly proposed parameters (L1 and L2) do not have obvious taxonomic affinity, but they do highlight the differences between the two submorphotypes. Based on our results, boundaries of these morphometric characteristics are proposed to separate the two submorphotypes explicitly. For L1, the critical values are: L1 > 2 for CRE_LOB and L1 < 1 for CRE_SIN. L2 is the most accurate morphometric characteristic for distinguishing submorphotypes, and an exact value for such classification is proposed: CRE_SIN < 1.35 < CRE_LOB.