Premise of the study: Parasites with large geographic ranges, and different hosts in parts of their range, might acquire horizontally-transferred genes (HGTs), which might sometimes leave a footprint of gradual host and range expansion. Cynomorium coccineum, the only member of the Saxifragales family Cynomoriaceae, is a root holoparasite that occurs in water-stressed habitats from western China to the Canary Islands. It parasitizes at least ten angiosperm families from different orders, some of them only in parts of its range. This parasite therefore offers an opportunity to trace HGTs as long as parasite/host pairs can be obtained and sequenced. Methods: By sequencing mitochondrial, plastid, and nuclear loci from parasite/host pairs from throughout the parasite’s range and with prior information from completely assembled mitochondrial and plastid genomes, we detected ten HGTs of five mitochondrial genes. Key Results: The ten HGTs appear to have occurred sequentially as C. coccineum expanded from East to West. Molecular-clock models yield Cynomorium stem ages between 66 and 156 Myr, with relaxed clocks converging on 66–67 Myr. Chinese Sapindales, probably Nitraria, were the first source of transferred genes, followed by Iranian and Mediterranean Caryophyllales. The most recently acquired gene appears to come from a Tamarix host in the Iberian Peninsula. Conclusion: Data on HGTs that have accumulated over the past 15 years, along with this discovery of multiple HGTs within a single widespread species, underline the need for more whole-genome data from parasite/host pairs to investigate if and how transferred copies coexist with, or replace, native functional genes. In compliance with data protection regulations, you may request that we remove your personal registration details at any time. (Use the following URL: https://www.editorialmanager.com/ajb/login.asp?a=r) Please contact the publication office if you have any questions.