Plant Assessment Matrix

The Colorado Invasive Plant Assessment table categorizes non-native plants that threaten the state’s agricultural productivity and native ecosystems. Categorization is based on an assessment of the impacts of the plant on agricultural and native systems. The inventory represents the best available knowledge of invasive plant experts in the state. The Noxious Weed program uses a  Plant Assessment Form word document and Weed List Criteria word document to evaluate plant species of interest.

Inventory Categories


Each plant on the list received an overall rating of High, Moderate or Limited based on evaluation using the criteria system. The meaning of these overall ratings is described below. In addition to the overall ratings, specific combinations of section scores that indicate significant potential for invading new ecosystems triggers an Alert designation so that land managers may watch for range expansions. Some plants were categorized as Evaluated But Not Listed because either we lack sufficient information to assign a rating or the available information indicates that the species does not have significant impacts at the present time.

High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
Moderate – These species have substantial and apparent—but generally not severe—ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
Limited – These species are invasive but their ecological impacts are minor on a statewide level or there is not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.

Plant Assessment Matrix excel spreadsheet
(Complete Matrix)


Matrix Summary

Scores:* Regions:   Region Assessment
A = Severe NW = Northwest
B = Moderate SW = Southwest
C = Limited FR= Front Range
D = None D = Denver
U = Unknown SC= South Central
  NW = Northeast
*For Use With
Complete Matrix
SE= Southeast
  NP = Not Present in State
  U = Unknown

 

Common Name/
Scientific Name
Wildlands Rating
/ Alert?
Agriculture Rating
/ Alert?
Doc. Advisory Committee Recomm. Regions Habitats of Concern
and Comments
sericea lespedeza/
Lespedeza cuneata
Limited Limited 3.4 Down-list from List A to Watch NP wet meadows, shortgrass prairies, tallgrass prairies, hay meadows, roadsides, and pine woodlands
yellow nutsedge/
Cyperus esculentus
Moderate Moderate 3.2 Down-list from List B to List C U agricultural systems, especially irrigated land, as well as a few wetter grassland/rangeland
giant salvinia/
Salvinia molesta
High
X
Moderate 3.4 Keep as List A NP lakes, ponds, reservoirs, rivers, streams and canals
quackgrass
Elytrigia repens
High Moderate 3.0 Keep as a B List NW, NE widespread throughout the US. Invades oak, aspen, sagebrush, grasslands, mountain meadows, and prairie.
hydrilla
/ Hydrilla verticillata
High
X
High
X
2.3 Keep as A List NP lakes, ponds, reservoirs, rivers, streams and canals
wild caraway/
Carum carvi
Moderate Moderate 3.1 Keep as a List B FR disturbed areas, along roadsides, along ditches, hay fields, and mountain meadows. A serious problem in hay production and pasture systems.
Eurasian watermilfoil/
Myriophyllum spicatum
High
X
High
X
2.4 Keep as B List FR, D, SC lakes, ponds, reservoirs, rivers, streams and canals
giant reed /
Arundo donax
High
X
Moderate
X
3.1 List A D growing along lakes, streams, drains and other wet sites. Water usage is high in support of its rapid growth.
Japanese knotweed/
Polygonum cuspidatum
Moderate
X
High
X
2.2 List A NW, FR, D roadsides, throughout riparian areas, in wetlands, and in urban areas or other disturbed sites with adequate moisture
elongated mustard /
Brassica elongata, Erhr. ssp. integrifolia
Limited High
X
3.8 List A SC roadsides and in other disturbed soils under a variety of climatic conditions including; high salinity, extreme temperatures, and varied elevations. Pinion-Juniper woodlands, other desert/semi-arid communities.
bulbous bluegrass/
Poa bulbosa
Limited Moderate 2.4 List C NW, FR short/tall grass prairie, hay meadows, urban areas, and sagebrush/foothills scrublands
arrowhead/
Sagittaria sagittifolia
Limited Moderate 3.5 unlisted NP Ponds, canals and slow flowing water on muddy sub-strata in shallow water
common iceplant
Mesembr-yanthemum crystallinum
Limited Limited 2.9 unlisted SW gardens and disturbed areas
grass leaf matt daisy/
Hirpicium armeriodes
Eval no list Eval no list 0.0 unlisted SW gardens
matrimony vine/
Lycium barbarum
Limited Limited 2.2 unlisted D praires, wet meadows, scrublands, and urban areas where plants are being cultivated. Grown for Goji Berries.
Siberean Peashrub/
Caragana arborescens
Moderate Limited 3.0 unlisted FR, D This species prefers to grow in forested gaps. This could include many types of forest at a wide range of temperatures/elevations.
tree of heaven/
Ailanthus altissima
Limited Moderate 2.0 unlisted SW, FR, D Urban areas, especially along roads causing damage to sewers, foundations, sidewalks, roadways, and power lines. Riparian areas and other natural areas are susceptible.
wild parsnip/
Pastinaca sativa
Limited Moderate 3.9 unlisted NW, FR,SC, SE Escapee from cultivation. Grows in disturbed sites, along roads and ditches and in abandoned agriculturallands
yellow bedstraw/
Galium verum
Limited Moderate 3.5 unlisted NW Hay meadows, dryland crops, urban, exurban, and industrial
yellow sweetclover/
Melilotus officinalis
Moderate Moderate 2.6 unlisted NW, FR, D Found across the state, and is particularly present in urban areas, hay meadows, and scrublands
Sahara mustard/
Brassica tournefortii
High
X
Moderate
X
3.0 watch NP Thrives in gravelly soils and disturbed areas and desert environments.
baby's breath/
Gypsophila paniculata
Moderate
X
Moderate 3.2 Watch FR, D, SC Shortgrass prairies, hay meadows, ponderosa pine forests, ornamental plantings, and roadsides.
common bugloss/
Anchusa officinalis
Moderate Moderate 2.8 Watch NW Hay meadows, pastures, rangelands, and disturbed areas. It is commonly cultivated as an ornamental.
common reed/
Phragmites australis
Moderate Limited 3.3 Watch U Found in level, wet, muddy or seasonally flooded (less than 20") sites, such as: roadside ditches, marshes and wetlands, along the edges of lakes and ponds and other riparian areas.
flowering rush/
Butomus umbellatus
Limited Moderate 3.0 Watch NP Generally found in shallower portions of lakes, riparian zones along slow moving rivers and streams and in wetlands and marshes. Deeper water infestations are possible.
hairy willow-herb/
Epilobium hirsutum
Limited Limited 2.2 Watch FR, D Low pastures, ditches, wetlands, stream banks, fields and meadows.  Often found growing in the same habitat as and can co-exist with purple loosestrife.
Himalayan blackberry/
Rubus armeniacus
Moderate
X
High
X
3.1 Watch U wet meadows, mid-elevation, moist pine, spruce forests as well as riparian shrublands in the Foothills region.
Japanese blood grass/ cogongrass/
Imperata cylindrica
High
X
Moderate
X
2.9 Watch U Ornamental, with potential to invade grasslands, fields, riparian areas, flood plains, dry scrubs, pastures, roadsides, and disturbed sites. Colorado climate may control invasions but cold tolerant cultivars may be a threat.
onionweed/
Asphodelus fistulosus
Moderate
X
Moderate
X
2.4 Watch U Serious problem in climates like California and Australia, where there is abundant moisture for growth during establishment. Drought hardy after establishment.
pampas grass/
Cortideria jubata
Moderate
X
High
X
3.4 Watch D Riparian shrublands, developed lands, as well as low elevation dunes, rock outcrops, and canyonlands.
scotch broom/
Cytisus scoparius
Limited Moderate
X
3.2 Watch U Can occur in open forests, riparian corridors, and grasslands
swainsonpea/
Sphaerophysa salsula
Eval no list High
X
3.2 Watch D Most commonly foundin distrubed areas such as roadsides, ditches, and poor soils.
Syrian beancaper/
Zygophyllum fabago
Moderate
X
Moderate 2.6 Watch NW Thrives well is areas that are dry and contain alkaline soils
water hyacinth/
Eichhornia crassipes
High
X
Moderate
X
3.0 Watch NP Is capable of establishing in a wide range of aquatic systems
water lettuce/
Pistia stratiotes
Moderate
X
Moderate
X
2.9 Watch NP Can become established in lakes, ponds, reservoirs, streams, rivers and canals
white bryony/
Bryonia alba
High
X
Moderate
X
2.6 Watch U Riparian and wetland areas as well as woodland areas may be at risk.
woolly distaff thistle/
Carthamus lanatus
Moderate
X
Moderate 2.2 Watch NW Pastures, rangeland, and disturbed areas.
bathurst burr, spiney cocklbur /
Xanthium spinosum
Limited Moderate 3.2 Watch SE, SC Riparian areas, irrigated pastures, hay meadows, shrublands, and waste areas.
meadow hawkweed
Hieracium Caespitosum
High
X
Moderate
X
1.9 Watch U can spread rapidly across abandoned pastures, meadows, and clear-cut areas due to its prodigious stolon growth.