RMD-13-04: Consolidated Pest Risk Management Document for pest plants regulated by Canada
Executive Summary

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This risk management document (RMD) is part of a three step pest risk analysis process examining the risk to Canada associated with the importation, cultivation and trade of pest plants listed in Table 1: List of plant regulated as pest plants in Canada. The RMD provides a summary of the pest risk assessment for each pest plant, and potential risk mitigation measures. Mitigation measures may be applied to reduce the pest risk to acceptable levels and provide a cost-effective means of preventing the entry of pests into Canada. Although stakeholders were consulted on the individual RMDs in 2010, the general information and considerations for each pest were similar. As such the original RMD information has been combined into one decision document. Invasive plants are those plant species that spread when introduced outside of their natural past or present distribution and cause serious and often irreversible damage to Canada's ecosystems, economy and society.

The pest plants listed in Table 1 could establish in parts of Canada. Following stakeholder consultation in 2010, the Canadian Food Inspection Agency (CFIA) has decided to regulate these pest plants under the Plant Protection Act and the Seeds Act. As such, the plants listed in Table 1 will be regulated as pest under the Plant Protection Act, and placed on the List of Pests Regulated by Canada. The Plant Protection Act gives CFIA the authority to take action and respond to incursions of the pests in Canada. Furthermore, when a seed is a key pathway, the CFIA plans to designate some of these plants as prohibited noxious weed seeds under the Seeds Act's Weed Seeds Order.

Table 1: List of invasive plants to be regulated as pest in Canada
Species Hardiness ZoneTable Note 1
and Distribution
Sector(s)/Habitat Affected Agricultural, Environmental and/or Societal Impacts Potential Human Mediated Pathways of Entry
1. Aegilops cylindrica(jointed goatgrass/Égilope cylindrique) Aegilops cylindrica

Hardiness Zone 2
Canada: ON/B.C. (under official control)
Other: US, Mexico, Asia, Europe

  • Agriculture: cereal crops (primarily winter wheat and also spring wheat) and pasture
  • Environment: disturbed areas such as railways
  • Losses in crop yield and quality in the U.S. estimated at $150 million annually.
  • Field experiments demonstrated a first year infestation of 1 to 5 plants per square metre led to yield losses of 3 to 30% the following year.
  • Presence of spikelets has been shown to lower wheat grade in the U.S. and cause dockage losses in winter wheat.
  • Reduction in planting of winter wheat, a component of reduced-tillage systems.
  • Potential for hybridization with herbicide tolerant wheat varieties if A. cylindrica is allowed to establish.
  • Contaminated farm machinery
  • Spillage of grain from trucks and rail cars
  • Contaminated grain lots (particularly winter wheat), straw and livestock
2. Alopecurus myosuroides (slender foxtail/Vulpin des champs)
Alopecurus myosuroides

Hardiness Zone 6
Canada: absent
Other: US, Africa, Asia, Europe, South America, Australia, New Zealand

  • Agriculture: winter cereal crops and pasture
  • Environment: moist meadows, deciduous forests and disturbed ground
  • Most damaging weed of winter cereals in Europe.
  • Difficult to eradicate from cultivated fields. Populations in England have developed resistance to several grass herbicides.
  • Contaminated grass seed, cereal grains, hay, straw, and manure
3. Centaurea iberica (Iberian starthistle/Centaurée ibérique )
Centaurea iberica

Hardiness Zone 6
Canada: absent
Other: US, Europe, Asia

  • Agriculture: range and pasture, hay
  • Environment: roadsides
  • Social: recreational areas
  • Displaces valuable forage species in pastures and rangelands.
  • Its sharp spines deter grazing animals, restricting access for livestock and reducing the value of hay.
  • Infestations can impede recreational use and restrict access for wildlife.
  • Contaminated clover seed
  • Livestock
  • Raw wool and raw hides
4. Centaurea solstitialis (yellow starthistle/Centaurée du solstice)
Centaurea solstitialis

Hardiness Zone 5
Canada: absent
Other: US, Europe, Asia, South America

  • Agriculture: horses, rangelands, cereals, orchards, vineyards, cultivated crops
  • Environment: roadsides, wastelands
  • Social: recreational areas, private land
  • Toxic in large amounts to horses.
  • Losses due to interference with livestock grazing and forage harvesting procedures.
  • Lower yield and forage quality of rangelands. Livestock avoid grazing in heavily infested areas resulting in slower weight gain and reduced quality of milk, meat, wool and hides.
  • Reduces wildlife habitat and forage, displaces native plants, decreases native plant and animal diversity, alters the water cycle (by using more water to a greater soil depth) and fragments habitat.
  • Can limit access to recreational areas and reduce land value.
  • Contaminated alfalfa seed, cereal grain, hay and nursery stock with soil
  • Movement of vehicles, equipment and livestock
5. Crupina vulgaris (common crupina/Crupine vulgaire )
Crupina vulgaris

Hardiness Zone 4
Canada: absent
Other: US, Europe, Asia, Africa

  • Agriculture: pastures, rangelands, hayfields, livestock
  • Environment: undisturbed roadsides, waste places
  • Could have serious economic impacts on forage and livestock production.
  • Can be highly competitive and dominate sites, displacing other plant species and reducing biodiversity. It also increases the risk of soil erosion.
  • Intentional import by tourists and recreational users
  • Contaminated hay and seed
  • Clothing on travellers
  • Vehicles and equipment
  • Livestock
  • Wool
6. Dioscorea polystachya (Chinese yam/Igname de Chine)
Dioscorea polystachya

Hardiness Zone 5
Canada: absent
Other: US, China, Japan, Korea, Taiwan

  • Environment: forests, scrub, herbaceous plant communities, mountain slopes, granite outcrops, along rivers, creek bottoms, roadsides, drainage canals, waste places, fence rows
  • The large, edible tuber is flavourful and nutritious and is sometimes used in herbal medicine. Processed or dried roots can be imported rather than the plant being grown in Canada.
  • The species is often planted for its ornamental value.
  • Reduces native species richness and abundance and can cause branches of trees and shrubs to break.
  • Manual and mechanical treatment methods are very time and labour-intensive; repeated herbicide treatments are necessary to kill underground tubers.
  • Intentional introduction as an ornamental, medicinal plant or tuber crop
7. Echium plantagineum (Paterson's curse/Vipérine à feuilles de plantain)
Echium plantagineum

Hardiness Zone 5
Canada: SK
Other: US, South Africa, Russia, Uruguay, Argentina, Brazil, New Zealand, Saudi Arabia and United Arab Emirates.

  • Agriculture: pastures, horses, sheep
  • Environment: soil stability and productivity, threat to native species
  • Pasture degradation, livestock and crop yield losses (e.g. cereals, hay and seed contamination and increased costs of control
  • Ability to dominate pastures in its exotic range, toxicity to livestock and potential control issues due to herbicide resistance.
  • May have a negative impact on the quality of Canadian honey.
  • This species is a host of four plant pests
  • Intentional introduction as an ornamental, industrial crop for commercial production,
  • Fur of domestic animals
  • Indigested seed
  • Contaminated vehicles and equipment
  • Contaminant of hay, soil, gravel or cereal and forage seed
8. Microstegium vimineum (Japanese stiltgrass/Aucun nom commun français répertorié)

Microstegium vimineum

Hardiness Zone 5
Canada: absent
Other: US, India, Nepal, China, Japan

  • Agriculture: crop production areas, landscape plantings and turfgrass
  • Environment: stream banks, moist woodlands, old fields and thickets, utility rights-of-way, roadsides, lawns, wetlands, ditches
  • Once established, can crowd out native herbaceous vegetation in wetlands and forests within 3 to 5 years.
  • Disrupts the quality of nesting habitats for birds
  • Can alter natural soil conditions (e.g. higher pH), creating an inhospitable environment for many native species.
  • Rapid growth leads to the creation of “mats” on the forest floor that negatively affects native woody species regeneration.
  • Contaminant of bird seed, soil, nursery stock, and hay
  • Packing material
  • Fur of animals
  • Human clothes and boots
  • Vehicles
9. Nassella trichotoma (serrated tussock /Stipe à feuilles dentées)

Nassella trichotoma

Hardiness Zone 7
Canada: absent
Other: South America, Australia, New Zealand

  • Agriculture: pasture and range
  • Environment: grasslands and lightly forested terrain
  • The cost to control moderate to heavily infested land in New Zealand was estimated at $98.50 to $107.35 per hectare. Continued treatment must occur for up to 22 years before an economic benefit can be expected.
  • Can out-compete native grasses, threatening the endangered Garry Oak Meadows ecosystem of south-western BC.
  • Heavy infestations of conservation lands decrease their biological diversity and aesthetic value.
  • Reduces carrying capacity of pastures due to its low nutritive value and poor palatability to livestock, but most pastures in Canada are outside of its potential range.
  • Intentional import as an ornamental (seed and plants for planting)
  • Contaminant of seeds of forage grasses, hay and raw wool
  • Live woolly animals
10. Paspalum dilatatum (Dallis grass/Herbe de Dallis)
Paspalum dilatatum

Hardiness Zone 6
Canada: absent
Other: US, South America, southern Europe, tropical and southern Africa, Asia, Australia, New Zealand, Oceania

  • Agriculture: potatoes, vegetables, pastures, orchards, vineyards
  • Environment: heaths, shrubland, riparian habitats, freshwater wetlands, swamps, lawns, roadsides, disturbed and natural clay pans
  • Considered a weed of 14 crops in 28 countries.
  • Weed problem on lawns, golf courses and other turf areas where it is very difficult to control.
  • Smothers low-growing plants and prevents recruitment of native woody species.
  • Contaminant of turf grass seed, bird seed and grain
  • Deliberate introduction as a forage plant
11. Persicaria perfoliata (mile-a-minute weed/Renouée perfoliée)

Persicaria perfoliata

Hardiness Zone 6
Canada: absent
Other: US, Asia (most prominent in Japan, Korea and China), Turkey, Caribbean

  • Agriculture: nurseries, Christmas tree plantations, forage crops
  • Environment: disturbed and riparian areas
  • Social: parks and private land
  • Coined “kudzu of the north”
  • Affects production of trees and shrubs (nurseries) and Christmas tree plantations.
  • Increased costs of control to the transportation industry, parks and recreation and home gardeners.
  • Reduces native plant diversity, invades sensitive riparian areas and impoverishes food and habitat for native wildlife.
  • Reduces the aesthetic value of properties and public areas. Its prickly vines are a nuisance to people and pets.
  • Seed or plants associated with nursery stock
  • Contaminated seed (e.g. Meliosma and Ilex)
  • Contaminated hay or straw
  • Vehicles and equipment
12. Senecio inaequidens (South African ragwort/Séneçon du cap)

Senecio inaequidens

Hardiness Zone 6
Canada: absent
Other: southern Africa, Europe, Taiwan, Mexico, Argentina, Colombia

  • Agriculture: range, pasture, vineyards, livestock, crops
  • Environment: grasslands, stream margins, ruderal habitats, railway lines, roadsides, river ports, flat roofs, flower tubs, logging areas, storm-damaged forests, industrial sites, disused quarries, rocky sites, coastal dunes
  • Capable of modifying landscapes and invading natural habitats such as dunes and cliffs.
  • The plants are toxic to livestock and humans. The pyrrolizidine alkaloids have the potential to contaminate milk and honey products.
  • Control and/or eradication in Europe are considered difficult and costly. Negative economic consequences associated with herbicide resistance have been reported from German railways to be 100,000 Euros per year.
  • Its establishment could threaten Canada's ability to export commodities to the U.S. where it is a federal noxious weed.
  • Contaminant of hay, grain, wool, ornamental plants and containers
  • Association with livestock and people
13. Senecio madagascariensis (Madagascar ragwort/Séneçon de Madagascar)

Madagascar ragwort

Hardiness Zone 8
Canada: absent
Other: southern Africa, Madagascar, Réunion, Mauritius, Argentina, Colombia, Australia, Japan

  • Agriculture: pastures, rangelands, cultivated land
  • Environment: yards, fields, roadsides, disturbed land, coastal plains
  • Strong competitor with desired pasture species, reducing pasture productivity.
  • Toxic to poultry, pigs, cattle and horses.
  • Costs due to herbicide use and toxic effects on cattle were estimated to be $11 million ten years ago in Australia (in non-drought years).
  • Its introduction could threaten Canada's ability to export commodities to the U.S. where it is a federal noxious weed.
  • Negative effects on biodiversity by competing with native vegetation such as grass and low-growing plants.
  • Changes to the vegetation composition of an area could promote soil erosion.
  • Contaminant of seed
  • Association with travellers and their effects
14. Solanum elaeagnifolium (silverleaf nightshade/Morelle jaune)

Solanum elaeagnifolium

Hardiness Zone 5
Canada: absent
Other: US, Mexico, South America, Australia, India, South Africa, Mediterranean basin

  • Agriculture: cereals (wheat, sorghum, corn), soybeans, alfalfa, vegetables, grapes, some fruit trees, cultivated pastures, livestock corrals
  • Environment: disturbed areas, roadsides, railways, riverbanks, canal-sides, construction sites, wastelands
  • Considered one of the “worst weeds of the west.”
  • Presence of the weed decreases yield and reduces quality and sale when found in harvested products.
  • In Morocco, the value of infested fields reportedly decreased by 25%, while in the U.S. entire farms have been abandoned.
  • The average total farm cost for this weed in the wheat belt of Victoria, New South Wales and South Australia was $1,730 (AUD) per year for control and $7,786 (AUD) per year in production losses.
  • May replace native vegetation in overgrazed rangeland.
  • Loss of value of agricultural land infested with the weed.
  • Contaminant of forage and crop seed (corn), hay, straw and grain
  • Livestock and manure
  • Vehicles and agricultural machinery
  • Nursery stock with soil
  • Possible natural dispersal
15. Zygophyllum fabago (Syrian bean-caper/Fabagelle)

Zygophyllum fabago

Hardiness Zone 5
Canada: absent
Other: US, Asia, Europe, Australia

  • Agriculture: rangeland
  • Environment: roadsides, corrals, gravel pits
  • Considered one of the “worst weeds of the west.”
  • Can dominate native vegetation in dry habitats.
  • Forms dense masses that displace beneficial species on rangelands.
  • Control with herbicides is difficult due to its waxy leaf surfaces and extensive root system.
  • Toxic to livestock, so infestations decrease available forage.
  • Intentional import for planting (as plants for planting and seed)
  • Contaminated alfalfa seed
  • Vehicles


As described by the International Plant Protection Convention (IPPC), Pest Risk Analysis (PRA) includes three stages: initiation, pest risk assessment and pest risk management. Initiating the PRA process involves identifying pests and pathways of concern and defining the PRA area. Pest risk assessment provides the scientific basis for the overall management of risk. Pest risk management is the process of identifying and evaluating potential mitigation measures which may be applied to reduce the identified pest risk to acceptable levels and selecting appropriate measures.

This Risk Management Document (RMD) includes a summary of the findings of a pest risk assessment and records the pest risk management process for the identified issue. It is consistent with the principles, terminology and guidelines provided in the IPPC standards for pest risk analysis.

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