Drought stress effect on morphological and physiological characteristics of different varieties of annual verbena (Verbena hybrida) Journal title: Journal of Biodiversity and Environmental Sciences (JBES) Authors: Salman Shahzad, Usman Khalid Chaudhry, Bilal Anwar, Abdul Saboor, Muhammad Farhan Yousaf, Faisal Sae... Subject(s): Biological Sciences, Environmental Sciences, Biology