Water hyacinth introduced to the United States

Background. Pontederia crassipes, commonly known as common water hyacinth, is an aquatic plant native to South America. It has been widely introduced in North America, Europe, Asia, Australia, Africa, and New Zealand. In the introduced range, the M-morph prevails, with the L-morph occurring occasionally and the S-morph absent altogether.

Introduction Accounts. Various accounts exist regarding how water hyacinth was introduced to the United States. The claim that it arrived in 1884 at the World's Fair in New Orleans is characterized as the "first authentic account" or "local legend." A 1941 article states that Japanese staff imported plants from Venezuela and gave them away as souvenirs.

Early Observations. P. crassipes was found to have been offered in the 1884 issue of a Bordentown, New Jersey–based publication. Harper's Weekly magazine (1895) printed an anecdotal account stating that a certain man from New Orleans collected and brought home water hyacinths from Colombia, around 1892, and the plant proliferated in a matter of 2 years. By 1897 the plant was a recognized problem in Gulf states such as Florida and Louisiana, where the government dispatched a task force of the United States Army Corps of Engineers.