QuarterQuad Maps

Below are maps that depict the statewide distribution and abundance of selected noxious weed species in Colorado.

Data is requested from the County Weed Supervisors on an annual basis (no mapping was done in 2003) and infested acreages estimates are per 9,000 acre QuarterQuad. A QuarterQuad is one quarter of a standard 1:24,000 U.S.G.S. 7.5min topographic quadrangle.

Each block of color represents an infested 9,000 acre area: lighter red blocks indicate the presence of relatively light or new infestations, while darker red blocks indicate the presence of a greater number of infested acres within the QuarterQuad. Counties that have not reported their weed infestations are indicated with a cross-hatch pattern.

For more specific locations of noxious weeds, you should contact the appropriate County Weed Manager.

Common Names Scientific Names
Absinth wormwood Artemisia absinthium
African rue Peganum harmala
Black henbane Hyoscyamus niger
Bouncing bet Saponaria officinalis
Bull thistle Cirsium vulgare
Canada thistle Cirsium arvense
Chinese clematis Clematis orientalis
Common teasel Dipsacus fullonum
Common tansy Tanacetum vulgare
Corn chamomile Anthemis arvensis
Cutleaf teasel Dipsacus laciniatus
Cypress spurge Euphorbia cyparissias
Dalmatian toadflax Linaria dalmatica
Dame's rocket Hesperis matronalis
Diffuse knapweed Centaurea diffusa
Dyer's woad Isatis tinctoria
Eurasian watermilfoil Myriophyllum spicatum
Hoary cress Cardaria draba
Houndstongue Cynoglossum officinale
Jointed goatgrass Aegilops cylindrica
Leafy spurge Euphorbia esula
Mayweed chamomile Anthemis cotula
Meadow knapweed Centaurea pratensis
Mediterranean sage Salvia aethiopis
Moth mullein Verbascum blattaria
Musk thistle Carduus natans
Myrtle spurge Euphorbia myrsinites
Orange hawkweed Hieracium auranticaum
Oxeye daisy Chrysantheum leucanthemum 
Perennial pepperweed Lepidium latifolium
Plumeless thistle Carduus acanthoides
Purple loosestrife Lythrum salicaria
Quackgrass Elymus Repens
Russian knapweed Acroptilon repens
Russian olive Elaeagnus angustifolia
Saltcedar (Tamarix) Tamarix parviflora 
Scentless chamomile Matricaria perforata
Scotch thistle Onopordum acanthium 
Spotted & hybrid knapweed   Centaurea stoebe & Centaurea maculosa Centaurea x psammogena = C. stoebe x C. diffusa 
Sulfur cinquefoil Potentilla recta
Wild caraway Carum carvi
Yellow nutsedge Cyperus esculentus
Yellow starthistle Centaurea solstitialis
Yellow & hybrid toadflax Linaria vulgaris & Linaria vulgaris x L. dalmatica

Historic Quarter Quad Data


Please email the Noxious Weed Program for historic noxious weed distribution data and maps.