BugwoodWiki Article

hydrilla
Hydrilla verticillata (L. f.) Royle

Overview

Appearance
Hydrilla verticillata is a submersed, rooted aquatic plant that can grow in water up to depths of 20 ft. (6.1 m). Plants can survive in depths up to 40 ft. (12 m) in non-turbid water.
Foliage
Leaves are whorled in bunches of 3-8, but most often with whorls of 5. The midribs of the leaves are reddish in color with the undersides having small, raised teeth. Leaves are 0.2-0.8 in. (5-20 mm) long, less than 0.1 in. (2 mm) wide and have serrated margins.
Flowers
Only the female flowers of this dioecious plant have been found in the United States, which means no viable seed are produced.
Fruit
Turions (stem tubers) are bud-like structures which can drop off the plant and successfully survive freezing or drought. Tubers from the rhizomes are another way these plants reproduce and increase their invasive potential.
Ecological Threat
Hydrilla verticillata forms dense mats at the surface of the water. The dense mats can restrict native vegetation, irrigation practices, recreation, hydroelectric production, and water flow. It can invade most slow-moving or still water systems. This plant is believed to be native to Asia or Africa, although it is widely spread across the globe. It was first introduced into North America as an aquarium plant in the 1950s.

Selected Images


1149127
1149127

hydrilla
Hydrilla verticillata
Plant(s)
USDA APHIS PPQ Archive
1624029
1624029

hydrilla
Hydrilla verticillata
Plant(s)
Raghavan Charudattan
5396743
5396743

hydrilla
Hydrilla verticillata
Foliage
Robert Vidéki
5396747
5396747

hydrilla
Hydrilla verticillata
Foliage
Robert Vidéki
5396748
5396748

hydrilla
Hydrilla verticillata
Foliage
Robert Vidéki
5274077
5274077

hydrilla
Hydrilla verticillata
Plant(s)
Leslie J. Mehrhoff
5345046
5345046

hydrilla
Hydrilla verticillata
Plant(s)
David J. Moorhead
5307063
5307063

hydrilla
Hydrilla verticillata
Seed(s)
Steve Hurst

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Most Troublesome / Most Common Agricultural Weed List
This map identifies those states that consider this species either most troublesome or most common in at least one commodity. For more information, visit the MTMC project page.

State Regulated List
Legend
   No Data for this state
   Troublesome or Common weed in one or more crops

Invasive Listing Sources

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Alismatidae
Order: Hydrocharitales
Family: Hydrocharitaceae
Genus: Hydrilla

Other System Links

Plants: HYVE3
Bayer: HYLLI
GRIN: 316414
ITIS: 38974
NPDN Pest: PCHAFBA
NPDN Host: 31579

Synonyms and Other Names

Other Common Names:
Florida elodea, water thyme, waterthyme

Categories

Category: Aquatic
Category: Forbs/Herbs