Hydrilla verticillata
Copyright, Vic Ramey, University of Florida
Hydrilla verticillata
Copyright, Vic Ramey, University of Florida
Hydrilla is an
aquatic
(water) plant which grows on long stems with many
leaves. Hydrilla grows in just
about any clean water, including lakes, ponds, rivers,
streams, and marshes.
It can survive in a few inches of water or in depths of up
to 20 feet. This fast-growing plant
was introduced in the United States as an aquarium plant,
but has escaped into the wild, where it can become a
problem. Hydrilla is rooted in the
soil, but if it gets pulled up, or loses contact with the
bottom, it will form thick mats on the water's surface. When
this happens, Hydrilla can block out light to other plants
and animals below. Hydrilla grows very fast.
If conditions are good, it will grow an inch in one day.
Hydrilla also gets very large. One Hydrilla stem can be over
25 feet long. Hydrilla leaves are about
1/2 inch long with a pointed tip and teeth
on the edges. Copyright, Vic Ramey,
University of Florida Hydrilla is a
perennial,
which means the leaves and stems die when the weather gets
cold, but the roots continue to live in the soil. When the
weather gets warm again, the roots
send up new stems and leaves. Hydrilla roots are called
tubers, and look a lot like small potatoes. When Hydrilla stems get
broken, the pieces can become new plants. Hydrilla can also spread
when it produces flowers. Hydrilla flowers are tiny and
white. They float on the surface, just above the
water.
Hydrilla is very competitive and can push out other plants, such as pondweeds.
Even though Hydrilla causes lots of problems for some species of plants and animals, it can help others by providing cover and shelter. Fish, frogs, turtles, and aquatic insects can all hide in Hydrilla and use it for protection. If the Hydrilla grows too thick, though, these animals may have trouble getting around it.
Some animals that eat Hydrilla include turtles and carp.
Copyright, Ann Murray, University of Florida
Relationships in Nature:
Animals
Using as Food Source Animals
Using as Shelter Associations
With Other Plants
Relationship to Humans:
Hydrilla can become a big problem when it grows too fast in an area. It can become so thick that it is impossible to swim, fish, or operate a boat through it. Scientists have been working on ways to control Hydrilla.