COONTAIL OR HORNWORT 



Ceratophyllurn demersum L. 



This perennial plant is found in sluggish streams and ditches and 

 is among the dominant aquatics in temporary ponds and newly formed 

 lakes. These are rootless plants that in early season grow upright, with 

 the lower portion anchored in the bottom mud. During late season 

 the plants are found floating near the surface. The finely divided leaves 

 are produced in whorls at stem nodes. The individual leaf is cut into 

 two to four forked divisions with occasional toothlike projections on 

 the margins (insert 1). The stem internodes are shortened toward the 

 tip, giving the shoot an appearance of a bushy tail, hence the common 

 name "coontail". 



Flowers and fruits are produced singularly in the axil of the leaf 

 whorls. The fruit is rarely observed. Vegetative overwintering is 

 accomplished by thickened and shortened shoot tips that develop late 

 in the season and break off and sink to the bottom soil to vegetate 

 during favorable growth periods. 



This plant can be confused with certain submersed water 

 buttercups without some scrutiny. The two plants can be distinguished 

 by the definite whorled leaf attachment and forked divisions of 

 Ceratophyllurn , unlike the fan-shaped submersed leaves of buttercup. 



Coontail, while not generally considered a serious submersed 

 aquatic weed, is often seen in irrigation systems and can be an aquatic 

 pest in small laterals and new systems. 



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