Invasive weeds aggressively replace native plants, devastating watersheds.

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Weed Information


What is a noxious weed?

The Nevada Revised Statutes (NRS) defines a noxious weed as "any species of plant which is, or likely to be, detrimental or destructive and difficult to control or eradicate." Legally, a noxious weed is any plant designated by a Federal, State or county government as injurious to public health, agriculture, recreation, wildlife or property. (Sheley, Petroff, and Borman,1999) A noxious weed is also commonly defined as a plant that grows out of place and is "competitive, persistent, and pernicious." (James, et al, 1991). All noxious weeds in Nevada are regulated by the Nevada Department of Agriculture (NDA).


Are invasive plants the same as noxious weeds?

Not necessarily, although many noxious weeds are invasive. Invasive plants include not only noxious weeds, but also other plants that are not native to this country or to the area where they are growing. The BLM considers plants invasive if they have been introduced into an environment where they did not evolve. As a result, they usually have no natural enemies to limit their reproduction and spread (Westbrooks, 1998). Some invasive plants can produce significant changes to vegetation, composition, structure, or ecosystem function. (Cronk and Fuller, 1995).


Are all weeds noxious weeds?

No. The term "weed" means different things to different people. In the broadest sense, it is any plant growing where it is not wanted. Weeds can be native or non-native, invasive or non invasive, and noxious or not noxious. Some weeds are simply known as common or nuisance weeds, which are weeds that have varying levels of negative impact and are normally not particularly invasive or difficult to control. Although these are plants are seen as bothersome and are ordinarily found throughout the state, they are are not regulated by the state.


Nevada Noxious Weed List

There are 47 noxious weed species recognized in Nevada. Click on any of the following to view an EDDMapS distribution map of each species (each map will open in a new tab). Please note that EDDMapS distribution maps are incomplete and based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org.

African mustard (Brassica tournefortii)

African rue (Peganum harmala)

Austrian fieldcress (Rorippa austriaca)

CLICK HERE TO SHOW MOREHIDE THIS LIST

Black henbane (Hyoscyamus niger)

Camelthorn (Alhagi maurorum)

Canada thistle (Cirsium arvense)

Common crupina (Crupina vulgaris)

Common St. Johnswort (Hypericum perforatum)

Crimson fountaingrass (Pennisetum setaceum)

Dalmatian toadflax (Linaria dalmatica)

Diffuse knapweed (Centaurea diffusa)

Dyer's woad (Isatis tinctoria)

Eurasian watermilfoil (Myriophyllum spicatum)

Giant reed (Arundo donax)

Giant salvinia (Salvinia molesta)

Goatsrue (Galega officinalis)

Hoary cress (Cardaria draba)

Horsenettle (Solanum carolinense)

Houndstongue (Cynoglossum officinale)

Hydrilla (Hydrilla verticillata)

Iberian starthisle (Centaurea iberica)

Johnsongrass (Sorghum halepense)

Leafy spurge (Euphorbia esula)

Malta starthistle (Centaurea melitensis)

Mayweed chamomile (Anthemis cotula)

Mediterranean sage (Salvia aethiopis)

Medusahead (Taeniatherum caput-medusae)

Musk thistle (carduus nutans)

Perennial pepperweed (Lepidium latifolium)

Perennial sowthistle (Sonchus arvensis)

Poison-hemlock (Conium maculatum)

Puncturevine (Tribulus terrestris)

Purple loosestrife (Lythrum salicaria)

Purple starthistle (Centaurea calcitrapa)

Rush skeletonweed (Chondrilla juncea)

Russian knapweed (Acroptilon repens)

Saltcedar (Tamarix spp.)

Scotch thistle (Onopordum acanthium)

Silverleaf nightshade (Solanum elaegnifolium)

Spotted knapweed (Centaurea biebersteinii)

Squarrose knapweed (Centaurea virgata var. squarrosa)

Sulfur cinquefoil (Potentilla recta)

Swainsonpea (Sphaerophysa salsula)

Syrian beancaper (Zygophyllum fabago)

Waterhemlock (Cicuta spp.)

Yellow starthistle (Centaurea solsitialis)

Yellow toadflax (Linaria vulgaris)


Noxious Weeds by Category

Category A noxious weeds are weeds that are generally not found or that are limited in distribution throughout the state. SHOW LIST
HIDE CATEGORY A

African rue (Peganum harmala)

Austrian fieldcress (Rorippa austriaca)

Swainsonpea (Sphaerophysa salsula)

Black henbane (Hyoscyamus niger)

Camelthorn (Alhagi maurorum)

Common crupina (Crupina vulgaris)

Dalmatian toadflax (Linaria dalmatica)

Dyer’s woad (Isatis tinctoria)

Eurasian water-milfoil (Myriophyllum spicatum)

Giant reed (Arundo donax)

Giant salvinia (Salvinia molesta)

Goatsrue (Galega officinalis)

Crimson fountain grass (Pennisetum setaceum)

Houndstongue (Cynoglossum officinale)

Hydrilla (Hydrilla verticillata)

Iberian starthistle (Centaurea iberica)

Common St. Johnswort (Hypericum perforatum)

Malta starthistle (Centaurea melitensis)

Mayweed chamomile (Anthemis cotula)

Mediterranean sage (Salvia aethiopis)

Purple loosestrife (Lythrum salicaria, L. virgatum & cultivars)

Purple starthistle (Centaurea calcitrapa)

Rush skeletonweed (Chondrilla juncea)

Sow thistle (Sonchus arvensis)

Spotted knapweed (Centaurea maculosa)

Squarrose knapweed (Centaurea virgata)

Sulfur cinquefoil (Potentilla recta)

Syrian bean caper (Zygophyllum fabago)

Yellow starthistle (Centaurea solstitialis)

Yellow toadflax (Linaria vulgaris)

Category B listed noxious weeds are weeds that are generally established in scattered populations in some counties of the state. SHOW LIST
HIDE CATEGORY B

Horsenettle (Solanum carolinense)

Diffuse knapweed (Centaurea diffusa)

Leafy spurge (Euphorbia esula)

Medusahead (Taeniatherum caput-medusae)

Musk thistle (Carduus nutans)

Russian knapweed (Acroptilon repens)

African mustard (Brassica tournefortii)

Scotch thistle (Onopordum acanthium)

Silverleaf nightshade (Solanum elaeagnifolium)

Category C listed noxious weeds are weeds that are generally established and generally widespread in many counties of the state. SHOW LIST
HIDE CATEGORY C

Canada thistle (Cirsium arvense)

Hoary cress (Cardaria draba)

Johnsongrass (Sorghum halepense)

Perennial pepperweed (Lepidium latifolium)

Poison-hemlock (Conium maculatum)

Puncture vine (Tribulus terrestris)

Salt cedar (tamarisk) (Tamarix spp.)

Spotted water hemlock (Cicuta maculata)


Relevant Links

For detailed information and photos of all noxious weeds listed in Nevada, see the NDA Noxious Weed List

You can also view the list of designated noxious weeds in NAC 555.010 by clicking here

For a glossary of plant terms used to describe noxious weeds, see the NDA Noxious Weeds Terms List

References

Cronk, Q., and J. Fuller. 1995. Plant Invaders: The threat to natural ecosystems. Chapman & Hall. New York

James, L., J. Evans, M. Ralphs, and R. Child, editors.1991. Noxious Range Weeds. Westview Press. Boulder, CO.

Sheley, R.,J. Petroff, M.. Borman, 1999. Introduction to Biology and Management of Noxious Rangeland Weeds, Corvallis, OR.

Westbrooks, R. 1998. Invasive plants, changing the landscape of America: Fact book. Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW). Washington, DC.