In the united states, purple loosestrife is a(n): a. exotic flowering plant that has caused relatively few problems for native species. b. vine with purple striped leaves that strangles the trees around which it grows. c. exotic flowering plant that has caused significant problems for native species. d. native flowering plant that has been exported to europe, where it has caused significant problems for native european species. e. native flowering plant nearly brought to extinction by competition from exotic plants.