The Speedwells, Veronica genus, have a religious origin for their genus name. All good Catholics are familiar with the Stations of the Cross, a series of 14 pictures or sculptures depicting the crucifixion of Jesus. Station number 6 depicts a lady named Veronica who felt pity for Jesus and gave him her veil to wipe the sweat and blood from his face. He did so and then gave it back to her. The blood and sweat left the imprint of his face on the cloth.
Perhaps one of the 500 species of Veronica reminded someone of a facial imprint of Jesus.