**3. Materials and Methods**

*3.1. Plant Material and DNA Extraction*

Fresh young leaves were collected in 2018 during field investigations in Saudi Arabia: *C. farinosa* in Jeddah (21◦26- 45.2-- N 39◦25- 22.9-- E) on 21 April, *C. glandulosa* in Jeddah (21◦26- 45.3-- N 39◦25- 22.9-- E) on 21 April, *M. crassifolia* in Makkah (21◦13- 17.4-- N 39◦49- 36.1-- E) on 28 April and *M. oblongifolia* in Jeddah (21◦28- 31.7-- N 39◦50- 36.8-- E) on 21 April. No permission was required to collect the plant samples. Species were identified and verified by Dr. Dhafer Alzahrani, Department of Biological Sciences, Faculty of Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. A voucher specimen was prepared and deposited in the herbarium of King Abdulaziz University, Jeddah with the accession numbers: *C. farinosa* (KAU27480), *C. glandulosa* (KAU27481) *M. crassifolia* (KAU27482), *M. oblongifolia* (KAU27483). Total genomic DNA was extracted from the samples using the Qiagen genomic DNA extraction kit, according to the manufacturer's protocols.
