Spermatophytes (seed plants): Angiosperms (flowering plants): Monocots: Alismatales
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Hydrilla verticillata
FAMILY
Hydrocharitaceae
Go to FSUS key
Dig deeper at SERNEC, a consortium of southeastern herbaria.
Check out EDDMapS.org to see where this has been reported.
Hydrilla is most similar to Egeria, but it possesses prickles along the leaf margins and also on the central leaf vein beneath. Read more at Vascular Plants of North Carolina.
Aquatic weeds can clog irrigation channels and cover lakes, threatening crops and wildlife. Read more -- Outlawed! Federal Noxious Weeds: The Aquatics.
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Hydrilla verticillata
FAMILY
Hydrocharitaceae
SYNONYMOUS WITH Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Hydrilla verticillata
SYNONYMOUS WITH Flora of North America
Hydrilla verticillata
COMMON NAME:
Hydrilla
To see larger pictures, click or hover over the thumbnails.
)
Keith Bradley kab_h_verticillata_74746
June Miami-Dade County FL
South Dade Wetlands
Stems and leaves near the surface look like bottle brushes, per Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007).
COMPARE
aquatic plants
)
JK Marlow jkm160914_166
September
SE-EPPC Aquatic Plant ID Workshop
Fresh leaves noticeably rough to the touch, per Weakley's Flora (2015).
)
JK Marlow jkm160914_166b
September
SE-EPPC Aquatic Plant ID Workshop
Leaves mostly 1-2cm long, with stout sharp teeth on margins and midrib beneath, per Weakley's Flora.
WEAKLEY'S FLORA OF THE SOUTHEASTERN US (4/24/22):
Hydrilla verticillata
FAMILY
Hydrocharitaceae
SYNONYMOUS WITH
PLANTS NATIONAL DATABASE:
Hydrilla verticillata
FAMILY
Hydrocharitaceae
SYNONYMOUS WITH
Floristic Synthesis of North America. BONAP (Kartesz, 2021)
Hydrilla verticillata
SYNONYMOUS WITH
Flora of North America
Hydrilla verticillata
711
Submersed aquatic (rooted); Forb
Perennial
Dioecious (a monoecious form exists north of SC)
Habitat: Ponds, lakes, rivers, often locally abundant, per Weakley's Flora
Non-native: Old World
Common (rare in Mountains of GA & SC) (rare in GA Piedmont)
CLICK HERE to see a map, notes, and images from Weakley's Flora of the Southeastern US.
Click here to see a map showing all occurrences known to SERNEC, a consortium of southeastern herbaria. (Zoom in to see more detail.)
This plant is causing problems in natural areas outside its native range, according to authorities such as:
- Alabama Invasive Plant Council, 2012
- Georgia Exotic Pest Plant Council, 2006
- Kentucky Exotic Pest Plant Council, 2013
- NC Department of Transportation
- SC Department of Natural Resources Aquatic Nuisance Species List, 2003
- SC List of Regulated Pest Plant Species, 2017
- Tennessee Exotic Pest Plant Council, 2009
- US Fish & Wildlife Service
- USDA Federal Noxious Weeds, 091820
- Virginia Department of Conservation and Recreation, 2014
IS THE PLANT "ARMED"?
Leaves have stout sharp teeth on margins and midrib beneath
LEAVES:
Simple
Whorls of 4-8
Margins toothed with stout sharp teeth
FLOWER:
Summer
Whitish sepals & translucent petals in female flowers, male reddish-brown
3 sepals in pistillate flowers
3 petals in pistillate flowers
Flowers solitary on elongate flexuous stalks
FRUIT:
Summer/Fall
Capsule
TO LEARN MORE about this plant, look it up in a good book!
- Field Guide to Aquatic Plants of Alabama (Lovell, 2007) p42
- Invasive Plants, Guide to Identification, Impacts and Control (Kaufman & Kaufman, 2007) p429
- Invasive Exotic Plants of North Carolina (Smith, 2008) p054
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