common hempnettle USDA PLANTS Symbol: GATE2
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Galeopsis tetrahit L.

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Taxonomic Rank: Magnoliopsida: Lamiales: Lamiaceae
Synonym(s): brittlestem hempnettle

Appearance
Galeopsis tetrahit is an herbaceous annual that grows to be 1-3 ft (0.3-0.9 m) tall. The simple to branched stems are square, swollen at leaf nodes, and covered with coarse, downward pointing hairs intermixed with shorter glandular hairs. It is native to Europe.
Foliage
The opposite leaves are from 1-5 in (2.5-12.7) long. They are simple, short-petioled, ovate-lanceolate to lanceolate, and sparsely pubescent on both sides.
Flowers
The flowers are borne in terminal clusters or axillary clusters. They can vary in color from purple to pink to white, are 0.5-0.75 in (1.3-1.9 cm) long and bilaterally symmetrical.
Fruit
The egg-shaped seeds are mottled and grayish brown.
Ecological Threat
G. tetrahit invades roadsides, open woods, pastures, and fields. It can create monocultures especially in disturbed areas. It is avoided by most grazers and is considered an agricultural weed. G. tetrahit is the host for potato fungus and several nematodes.

Selected Images from Invasive.orgView All Images at Invasive.org


Plant(s);
Michael Shephard, USDA Forest Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s); Galeopsis tetrahit, hemp nettle - white form
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Michael Shephard, USDA Forest Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Tom Heutte, USDA Forest Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Jamie Nielsen, University of Alaska Fairbanks, Cooperative Extension Service, Bugwood.org
Additional Resolutions & Image Usage

Plant(s);
Jamie Nielsen, University of Alaska Fairbanks, Cooperative Extension Service, Bugwood.org
Additional Resolutions & Image Usage

Foliage; Galeopsis tetrahit, hemp nettle - white form
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Stem(s); Galeopsis tetrahit, hemp nettle - white form
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Caleb Slemmons, National Ecological Observatory Network, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Tom Heutte, USDA Forest Service, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); Galeopsis tetrahit - hemp nettle
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); Galeopsis tetrahit - hemp nettle (white form)
Rob Routledge, Sault College, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.


Invasive Listing Sources: