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Non-Native Invasive Aquatic Plants in the United States
Center for Aquatic and Invasive Plants, University of Florida |
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Non-Native Invasive Aquatic Plants in the United States
Center for Aquatic and Invasive Plants, University of Florida |
pronounced: hid-ril-lah ver-ti-ki-lah-ta (long/short marks) (audio clip)
from:
"water plant with whorls of leaves"
Hydrilla verticillata is a submersed freshwater
herb which, as an invasive non-native weed, often forms dense
stands
from the bottom to the top of the water, sprawling across the surface, although it may also
be found as detached drifting mats. Hydrilla once was cultured
and sold as an aquarium plant.
Habitat:
The best way to track the spread of invasive aquatic plants may be to identify
the drainage basins (watersheds) they have been discovered in. Drainage maps give useful
information to eco-managers because drainage maps show precisely where the plants are, making
it easier for managers to infer where the plants might go next, and thus where to take preventive
measures.
How it got here:
Hydrilla verticillata continues to be sold through aquarium supply dealers and over
the Internet, even though the plant is on the U.S. Federal Noxious Weed
List.
Potential to spread elsewhere in U.S.:
Problems/Effects:
Control:
From the University of Florida Aquatic Weed Management Guide, Vandiver
1999:
What can you do?
Laws and lists:
Want to know more?
If you want to read the research yourself, perhaps to clarify or expand an area of information
contained here, or to help determine your own line of research, you are welcome to query the
world's largest collection of international scientific literature about aquatic, wetland and invasive
plants, the APIRS
bibliographic database, which contains more than 54,000 citations and their content
keywords. Or you might want to ask us to do
it for you and mail or e-mail the search results to you.
This is the literature about Hydrilla verticillata that was used to
develop this web page. More research items about this plant may be found at APIRS:
Habit:
Hydrilla verticillata (L. f.) Royle
Original description: Linnaeus 1782; Royle 1839
Hydrilla verticillata might be confused with at least two other submersed,
long-stemmed plants having small narrow leaves.
--elodea leaves occur in whorls of 3 around the stem,
Hydrilla verticillata leaves are in whorls of 4 to 8 around the stem
--egeria leaves are in whorls of 4-5; Hydrilla leaves are in
whorls of 4 to 8
Origin:
Distribution in the U.S.:
U.S. Drainage Distribution Map,
occurrences, and other information about Hydrilla verticillata was prepared by
C.
Jacono of the U.S. Geological Survey, Nonindigenous Aquatic Species Program, which is
located
on the USGS-NAS web site.
Due to decades of university, state and federal research and experience with Hydrilla
verticillata in the U.S., several methods have been developed to help in its management:
in some cases, lake drawdowns may help manage hydrilla by letting the
exposed plants die and decompose
the action of mechanical harvestors and chopping machines remove hydrilla
from the water and transport it to disposal on shore; chopping machines,
unfortunately, fragment the hydrilla plants and may actually increase the plant's distribution
biocontrol fish and insects have been introduced to control hydrilla. The
herbivorous (plant-eating) biological control fish, the Chinese grass carp,
has a good preference for hydrilla (Cassani). Learn much more about the Chinese grass carp
on this page of this web site. Other biological control work has been
done for
this species, including tuber-feeding weevils
and
leaf-eating flies.
registered aquatic herbicides do provide temporary control of hydrilla;
According to this Guide, ... copper, diquat, endothall and fluridone; As always, comply
with
federal law
by following the herbicide label instructions, permissible sites and application
rates.
First, clean your boat before you leave the ramp! Transporting
plant fragments on boats, trailers, and in livewells is the main introduction route to new lakes and
rivers.
But, there's plenty more you can do to help.
Hydrilla verticillata
Category I - "plants invading and disrupting native plant communities in Florida"
The information contained on this wep page was extracted from
published
scientific literature and agency reports. It is important to know that plant research, like most
areas of scientific research, is still relatively young and incomplete--much may have been
published about the physiology of one plant but not about its management; much may have been
published about how to culture and grow another plant but not about its natural ecology.
Thousands of research articles may have been published about one invasive plant, but perhaps
only a dozen about another.
Anecdotal information about Hydrilla verticillata would be appreciated by users
of this web site. Please submit anecdotal information, additional reference citations and
corrections for this page to
CAIP-WEBSITE@ufl.edu
More complete identification:
