Pretty yet pernicious, a water hyacinth flower (wikimedia.org)
While California Invasive Species Action Week is over, the invasives are still here, and, luckily, so are great articles detailing their history and their effect in North America. Water hyacinth (Eichhornia crassipes) is commonly referred to as the fastest growing plant in the world, and in California it lives up to its reputation, "In the course of one California growing season, one water hyacinth plant small enough to fit in the palm of your hand can grow to become a mat of floating vegetation covering almost 6,500 square feet of open water."
With an invasive that grows this fast, it helps to be educated. Check out this invasive in depth through the link below.