identifies as Coulter's hibiscus which probably isn't a native flower to this area. Birds could have migrated the seed here from someone's yard. My vote would be to leave it because it is pretty. In fact, I personally would leave ANY flowered plant that isn't a threat to the area. The green/blue color seen here on the flower tells us it may have been sprayed by chemicals by the trail maintenance group. Did they think this was an invasive grass?