Use of leaves properties to determine the taxonomical relationship degree of species of Genus Euphorbia L.

Abstract

This research displays of  the morphology of the leaves, the veins of the leaves and stomata types of 9 species of the genus Euphorbia L. that found in Syrian flora. A new venation type that discrip we proposed to  accept it as "Pseudo-Brochidodromous". The leaves of the studied species are characterized of  proposed new style. The study showed that the venation pattern in the lamina have significant differences in determining intercostal area and it has been identified two forms, the studied species are incorporated within the two forms. It proposes designation "Prostrata-Form" and "Helioscopia-Form". The "Prostrata-form" includes: E.prostrata, E. pilulifera, and the "Helioscopia-Form" includes: E. helioscopia, E. peplus,E. thamnoides, E. terracina, E. paralias, E. aleppica, E . falcata,. The  anatomical study of the bottom side of the leaves epiderm in the studied species clatified that they have 6 types of stomata complex: Anisocytic which also includes the two types (Anisotricytic, Anomocytic), Staurocytic, Tetracytic, these types found in 8 of the studied species and possessed the same species more than type, except in E. paralias is the type Hexacytic.

The resultes helped us to obtained a pylogenetic tree by conducting cluster analysis depending on 42 character of morphological characteristics and the venation pattern. Separated morphological phylogenetic tree to two under the clusters, which included the first two species, E. prostrata and E. pilulifera and by the similarity of 0.381, and

under the second cluster separated into clusters under the first annexation of the species E. falcata, E. aleppica, E. paralias, E. terracina , E. thamnoides, E. peplus, while the inclusion of the second  the species E. helioscopia by the similarity of 0.393; that has enabled us to formulated a taxonomic key for the studied species.