Integrating morphological characters, molecular markers, and distribution patterns to assess the identity of Blepharis species from Jordan

Background: Blepharis constitutes an important vegetative part of the Jordanian arid and semi-arid regions, yet whether one or more species occurs in this area is debatable. We addressed this question by assessing morphological characters and employing Inter-Simple Sequence Repeat (ISSR) markers on three populations of Blepharis: two Northern (lower slopes of Kufranjah valley and the Dead Sea region) and one Southern (Wadi al Yutm).
Results: Shoots from 19 randomly chosen Blepharis plants per population were harvested for morphological and molecular analyses. Spikes were lax and bract width was considerably shorter than length of the longest lateral spine in the Northern populations compared to the Southern population (P < 0.001). A multivariate linear discriminant analysis (LDA) distinguished the Northern populations from the Southern one largely by internode length, bract width, longest lateral spine length, and bract width to spine length ratio (P < 0.001). The ISSR analysis r...