Milfoil

Myriophyllum (water milfoil) is a genus of about 45 species of freshwater aquatic plants, with a cosmopolitan distribution. Its name comes from Latin, "myrio" meaning "too many to count", and "phyllum", meaning "leaf".

Because it is widely distributed and difficult to control, milfoil is considered to be the most problematic plant in parts of America. The introduction of milfoil can drastically alter a water body's ecology. Milfoil forms very dense mats of vegetation on the surface of the water. These mats interfere with recreational activities such as swimming, fishing, water skiing, and boating. Milfoil interferes with power generation and irrigation by clogging water intakes. The sheer mass of plants can cause flooding and the stagnant mats can create good habitat for mosquitoes. Milfoil mats can rob oxygen from the water by preventing the wind from mixing the oxygenated surface waters to deeper water. The dense mats of vegetation can also increase the sedimentation rate by trapping sediments.

Quote:

"By autumn 1987, the job interviews revealed that “like” was no longer a mere slang usage. It had mutated from hip preposition into the verbal milfoil that still clogs spoken English today."

http://www.city-journal.org/2011/21_1_snd-american-english.html