Interspecific hybridization is known to have stimulated some plant invasions, but little is understood about the consequences of hybridization in a novel range between non-native plant species that are already invasive. Yellow toadflax and Dalmatian toadflax invasions are widespread on public forest and rangelands throughout the western U.S. These species do not hybridize in their native Eurasian ranges, but hybrid populations have recently been identified at sites co-invaded by both toadflaxes in Montana, Idaho, Washington and Colorado. Hybrid toadflax grown in common garden experiments emerged from winter dormancy earlier, flowered sooner, and grew larger than the parent species, indicating that hybrid toadflax may be even more invasive than yellow and Dalmatian toadflax and could displace them. Hybrid toadflax poses new challenges, as we do not know whether current management strategies for yellow and Dalmatian toadflax will be effective on these novel recombinant populations.
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Dr. Sarah Ward is originally from the U.K. where she studied plant sciences for her B.S. degree at the University of London. She joined the faculty at Colorado State University after completing a Ph.D. in plant breeding there, but became more interested in bad plants than good ones and eventually quit breeding crops to work on weeds. Her current research focuses on the genetics of herbicide resistant weeds and non-native invasive plants.