In all of its glory as the queen of floating water plants, Eichornia ssp., better known as water hyacinth, has a rather dichotomous relationship with aquatic plant enthusiasts around the world. While its beauty is unparalleled by any other free-floating plant, its invasive nature has made it a pest in the eyes of many states and countries. Such a reputation is lethal when the plant in question is, in itself, a guest in most waterways throughout the world.
Today water hyacinth can be found growing prolifically in American fresh waterways of the Gulf states, Hawaiian Islands, and Pacific Northwest. Prior to 1884, this "weed" was located only in South America. Due to its mesmerizing beauty, water hyacinth was brought to New Orleans for a plant exposition where it soon was adopted and introduced to wetlands and ponds in the surrounding states.
Water hyacinth is a free-floating aquatic plant with black, feathery roots that dangle up to a foot beneath the surface of the water. Visible above the water surface is waxy, oval-shaped foliage that is a rich, green color. During the heat of the summer, shoots of exotic violet flowers tower over the already intriguing leaves making the beauty of this plant even more captivating. While a single water hyacinth can be up to 3 feet tall, they rarely float in isolation due to the nature of their propagation.
From a single plant extend rhizomes that each grow baby water hyacinths. In a short amount of time, the parent and baby plants create a mat of plant matter. Plants that break away from the mass are often carried by wind and water currents to a new location. From expiring flowers, water hyacinth drop seeds by which reproduction also occurs. The seeds sink to the bottom of the pond and lay dormant until a drought dries the water and allows the seeds to grow.
Eichornia ssp. is classified as a "tropical" water plant, thriving in temperatures ranging from 54-95 degrees Fahrenheit. While a solid freeze will kill the plant, a light frost will only disturb the foliage, allowing the roots to generate new green growth. As an aquatic plant, water hyacinth needs puddles of water to sustain itself. Water salinity is a detriment to its growth, while it tends to thrive in water rich in nitrogen, phosphorus and potassium.
Mats of water hyacinth held together by rhizomes are a detriment to free-flowing waterways around the world. These solid mats prevent water flow in rivers, create breeding grounds for mosquitoes and disrupt boat traffic. More severe problems prohibit sunlight from reaching the water surface, starve native species of plants and deprive fish of oxygen. In areas of introduced natural growth, water hyacinth is considered a pest.
While water hyacinth is deemed "the world's worst aquatic plant" by the state of Washington's Department of Ecology, it continues to be sold to water garden owners as an ornamental plant. Eichornia ssp. assists in controlling algae by shading the pond surface from sunlight. Likewise, the dangling, feathery roots are a breeding ground for fish and other aquatic wildlife.