Texas WiIdf lower's Red Keeps It a Species

摘要

It's tough to remain a separate species when close relatives live in the same place. That's apparently why a Texas wildflower, the annual phlox (Phlox drummondii), has light bluish purple blooms in the central part of the state but takes on a dramatically different hue in eastern Texas. There, it comes into contact with the blue-flowering pointed phlox (Phlox cuspidata), and the flowers of the annual phlox have evolved to become deep red.