Water
Hyacinths are the only large aquatic herb tha t can float on the
water unattached to the bottom.
They float on bloated air-filled hollow leaf stalks. Their roots
trail underwater in a dense mat.
The seeds are dispersed by birds and can remain viable for 15-20
years.
But the main method of reproduction is vegetatively, through stolons.
A single plant under ideal conditions can produce 3,000 others in 50
days and cover an area of 600 sq metres in a year.The fast-growing
Water Hyacinth soon becomes a noxious weed outside its native
habitat. Plants interlock in such a dense mass that a person could
walk on it.
They clog waterways preventing river travel, block irrigation
canals, destroy rice fields, ruin fishing grounds
Water Hyacinths are difficult (if not impossible) to destroy.
In the US, arsenic fire and explosives was used .Fire and explosives
were also attempted,
but the plants reproduce rapidly even from the tiniest fragment and
simply grew back.
The most effective measures are biological controls,
Two weevils, a moth and two types of fungi have been introduced to
successfully control the plant.
Other creatures that keep the plant in check include fish. Uses :it
was cultivated as pig food,
In their native habitat of the Amazon, Water Hyacinths provide food
for their natural predators which voraciously keep the plant in
check.
The annual flooding of the Amazon also flush out huge quantities to
sea each year. |