Carob tree Ceratonia siliqua L.,  is an evergreen endemic species found naturally in El-Jabal El-Akhdar region which is located immediately south of the coastal belt in the northeastern region of Libya. Morphological characteristics have been the main descriptive tool to characterize a given collection or germplasm, or to identify and differentiate wild type populations. Eighteen carob population were collected from six different sites in El-Jabal El-Akhdar area. Seven characters on discriminative pods were measured: the length, width, thickness, number of seeds, weight of pulp, and yield as well as one character to seeds: the weight seeds. The present study showed that the choice of pod characters to assess Libyan carob diversity is a useful and powerful tool. The means and standard deviations of morphometric characters measured in Libyan carob showed highly significant differences among the studied populations for all the examined characteristics. Differences in morphometric traits of carob pods and seeds among Libyan carob populations are primarily caused by genetic factors. The pod size of Libyan carob is considered to be the medium size (10.89 – 17.55cm).

The genetic diversity of wild thyme (Thymus capitatus) which growing  in southern parts of Al-Jabal Al-Akhdar region, Libya was studied by using cluster analysis of morphological traits (flower measurements). This study was aimed to establish the phylogenetic relationships based on floral parameters among accessions of thyme (T.capitatus). The five populations (accessions) of Libyan thyme were assigned into two clusters (clades) at the critical distance value of 22%. The 1stcluster  contained three populations that were included white-flowered, dotted white-flowered and violet-flowered accession, then the 1st cluster was divided into two sub-clusters by the critical distance value of 5%, the first sub-cluster contained two populations (white-flowered, dotted white-flowered accession). While, the second sub-cluster contained one population (violet-flowered accession). The 2nd cluster contained two populations which were purple-flowered and mosaic-flowered accessions. In conclusion, The flower measurements can be a preliminary tool to classify Libyan thyme (T.capitatus), and  floral parameters can be used in the classification of Libyan thyme accessions (populations).