Diario de ward123

The ancestors of the genus Veronica, like Veronica serpyllifolia, were perennial plants. Veronica serpyllifolia is most likely a perennial because of its preference for moist environments. However, within the genus, the annual strategy evolved 6 times independently. The evolution of these annuals within this genus is most likely due to the Messinian Crisis, the drying up of the Mediterranean Sea about 6 million years ago. Another cause to the evolution to annual strategies was the onset of summer drought in the Mediterranean climate about 2.8 million years ago. This is because annual plants have an evolutionary advantage to avoid drought stress by producing drought-tolerant seeds.