Published on October 21, 2014
Table of Contents 1.Invasive: Alligator Weed 2.Indicator: Northern Maidenhair Ferns 3. Threatened: Wild Hyacinth 4. Keystone: Sea otter 5. Endangered: Shortnose Sturgeon 6.Extinct: Tasmanian Tiger Alligator Weed ! Alternanthera philoxeroides , commonly known as alligator weed, is a perennial plant that is native to South America. In addition to South America, alligator weed can be found in many warm, wet climates around the world, such as the southeast states of the United States and Australia. The weed is considered both a terrestrial and aquatic plant, however, it is usually found in or near water. Alligator weed roots in wet soil and has sprawling, hollow stems that are either single or branched and the leaves are long and oval shaped. There is also a small white ower at the end of the stem that is fragrant and reminiscent of a clover. Alligator weed reproduces through seeds. The weed often intertwines with itself and forms extended mats over rivers or shorelines. In the water, the intertwined layers of alligator weed provide a habitat for many macro and micro aquatic organisms. ! Alligator weed is considered to be an invasive plant because the thick matting that occurs from the intertwining layers of stems has the ability to completely cover bodies of water. This blockage prevents canals, streams, and other small waterways from emptying rapidly, thus causing ooding. Any portion of the mat that breaks off can pile up against bridges and dams and cause obstructions. Also, the increase in shade caused by the matting of alligator weed leads to a reduction in oxygen levels underwater and threatens the lives of many species. ! Efforts to control alligator weed have merged with control efforts of water hyacinth. However, the cost to control these weeds is sizable and more research on alligator weed is being conducted to determine the actual damage and if there is any benet it leads to.