Echium plantagineum_C070-06
Photo courtesy UC Davis Weeds of California

Echium plantagineum Risk Assessment

Common names: Patterson's curse

Echium plantagineum -- California

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Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
June 12, 2016
Evaluation Time (hrs): 
2 Hours
Evaluation Status: 
Completed
Plant Information
Plant Material: 
If the plant is a cultivar, and if the cultivar's behavior differs from its parent's (behavior), explain how: 
Regional Information
Region Name: 
Climate Matching Map
These maps were built using a toolkit created in collaboration between GreenInfo Network, PlantRight, Cal-IPC, and Agricultural Sustainability Institute at UC Davis.
Climate Matching Maps PDF: 
Invasive History and Climate Matching
1. Has the species (or cultivar or variety, if applicable; applies to subsequent "species" questions) become naturalized where it is not native?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Native to southern Europe, widely naturalized (Jepson). Naturalized in: Africa East Tropical Africa: Kenya; Tanzania Macaronesia: Portugal - Azores Northeast Tropical Africa: Eritrea; Ethiopia South Tropical Africa: Zimbabwe Southern Africa: Lesotho; South Africa Australasia Australia: Australia New Zealand: New Zealand Northern America Eastern Canada: Canada - Ontario Northeastern U.S.A.: United States - Massachusetts, - New York, - Pennsylvania Northwestern U.S.A.: United States - Oregon Southwestern U.S.A.: United States - California Western Canada: Canada - Manitoba Southern America Southern South America: Argentina; Chile; Uruguay (GRIN).
Reference(s): 
2. Is the species (or cultivar or variety) noted as being naturalized in the US or world in a similar climate?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
Very High
Answer / Justification: 
Widely naturalized in Mediterranean climates (GRIN, Jepson), including California. Overlaps with California climate zones (Cal-IPC).
Reference(s): 
3. Is the species (or cultivar or variety) noted as being invasive in the U.S. or world?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
Very High
Answer / Justification: 
It has been introduced to Australia, South Africa and United States, where it is an invasive weed. It is listed as a noxious weed in all states of Australia, and described as invasive in South Africa and countries of South America. Opinions are divided on the weed status of E. plantagineum in crops. It is a weed that significantly reduces yield in lucerne (Medicago sativa) and wild oats where present. In the Western Australian cereal belt, E. plantagineum can crowd out growing crops, reduce grain yield and make harvesting difficult. It was not a serious crop weed because it is controlled by normal cropping techniques and, if necessary, spraying with 2,4-D. Instances of herbicide resistance have since been reported. The plant is rare in crops because most seed germinates in the summer and autumn when soil temperatures are high and seedlings are killed by cultivation before the crop is sown. The plant became a more important crop weed with the adoption of minimum-tillage crop establishment techniques (CABI). Paterson's curse (Echium plantagineum) is regarded as a significant environmental weed in Victoria, the ACT, South Australia, Western Australia and New South Wales, and an environmental weed in Tasmania, Queensland and the Northern Territory. It is very widespread and troublesome, recently being listed as a priority environmental weed in nine Natural Resource Management regions (Weeds of Australia Biosecurity Queensland Edition). Paterson’s curse has never been seen as a potential problem in California, as it has not been detected as spreading from introduction sites until now. It has never been subject to official control. Paterson’s curse has been in California a long time, but has not spread widely. Its behavior in Australia and the site in Sonoma suggest that it is just beginning its spread here in California (CDFA).
4. Is the species (or cultivar or variety) noted as being invasive in the US or world in a similar climate?
Yes or No: 
Yes
Points: 
3
Confidence Level: 
Very High
Answer / Justification: 
Invasive in all parts of Australia, South Africa, and parts of the U.S. (CABI; Weeds of Australia Biosecurity Queensland Edition). Overlaps substantially with California climate zones (Cal-IPC).
Reference(s): 
5. Are other species of the same genus (or closely related genera) invasive in a similar climate?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Of the 40 species in the genus Echium (all from Europe and Macaronesia), two other herbaceous species, both monocarpic perennials, have naturalized and spread outside their native range; Echium italicum and E. vulgare. E. italicum is a larger species with smaller pale flowers and occurs extremely locally in Australia and North America, while E. vulgare is most similar to E. plantagineum (except for smaller flowers and stamens more exserted) and quite widespread in temperate regions of Australasia, North and South America and South Africa. E. vulgare is more a cool temperate species, where it can be a common weed in some perennial pasture, roadsides and neglected areas. E. plantagineum has more rapid germination over a wider temperature range, more rapid vegetative growth, and greater capacity to flower under a wide range of temperature and photoperiod, than either E. italicum or E. vulgare. Given that members of Echium have strong horticultural interest based on their flowers, that several of these have become garden escapes (e.g., E. simplex, E. candicans and E. pininana), and that other species are weeds in their native range, many of the species in the genus are considered a threat on a global scale (CABI).
Reference(s): 
6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
Very High
Answer / Justification: 
Found predominantly in Europe (Mediterranean regions particularly), Brazil and other parts of South America, a large portion of Australia (particularly the southern one-third of the country), and New Zealand. Is also present in California, Oregon, and the northeastern U.S. (GBIF). A "A" designated quarantine weed in Oregon (USDA PLANTS). Hardy in zones 9a-10a (Calflora). Native to southern Europe, widely naturalized (Jepson). It is found in parts of the world with a Mediterranean climate. The evolutionary centre of the genus occurs in southern Spain, Portugal and Morocco, where the genus and its natural enemies show highest diversity. The genus has a secondary evolutionary centre of mainly monocarpic and polycarpic perennial species on the Canary Islands and Madeira that developed following the arrival of ancestral Echium species. E. plantagineum originates from the western Mediterranean region, but local colonization has led to a broadly circum-Mediterranean distribution, including also England and the Channel Islands, Madeira and the Canary Islands. E. plantagineum has been spread widely throughout the world and has become particularly well established in countries with Mediterranean-type climates including South Africa, southwest Russia, the western USA, Uruguay, Argentina and Brazil, and New Zealand. In addition to the listed distribution, there are unpublished records for Saudi Arabia and United Arab Emirates and, in the USA, Oregon and Washington. The extent and abundance of E. plantagineum is often greater in the exotic range than in the Mediterranean regions where it originated for a number of reasons: a) extensive agriculture, particularly pasture-based, is now more commonly practised in other Mediterranean parts of the world than in Europe; b) native vegetation in the regions is usually poorly adapted to compete with E. plantagineum in the presence of livestock grazing; and c) there are relatively few native natural enemies damaging the plant in the exotic range. Nonetheless, E. plantagineum can be a significant component of the flora in its native range, for example being described as a 'principal' weed in Tunisia and occasionally requiring some management in Spain. E. plantagineum is now common, and often abundant, throughout southwest Western Australia, central and southern South Australia, southeast Queensland, central and southern New South Wales, Victoria, Tasmania and the Northern Territory. At the edge of its range it is mostly limited to disturbances on roadsides. In New Zealand, E. plantagineum is abundant north of the volcanic plateau of the North Island and scattered to rare elsewhere. It is regarded as a weed in many places in south Africa. There are few reports on the significance of E. plantagineum in pastures in other parts of the exotic range (CABI). Hardy in zones 3a-8b (Dave's Garden). Substantial overlap with California climate zones (Cal-IPC).
Reference(s): 
Impact on Native Plants and Animals
7. Does this plant displace native plants and dominate (overtop or smother) the plant community in areas where it has established?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
Where introduced it has established and spread successfully in pastures where it can outcompete native species. E. plantagineum-rich communities in pasture, crops, or orchards are generally species-rich compared to those in the exotic range. In the exotic range, E. plantagineum occurs mainly in perennial and annual pastures on roadsides and in waste places, where it can often be dominant. In can spread as a casual into disturbed native grasslands or rough grassing grassland, but is not maintained there without at least the sporadic presence of livestock. Its conspicuous flowers and high density also affect the aesthetics of regions within which large infestations occur (CABI). It is primarily a weed of grazing land. Significant change to biomass unlikely. However, it competes “vigorously with smaller indigenous plants and impedes overstorey regeneration.” “The broad rosette leaves shade and smother most other species.” Major impact on lower stratum, minor impact on mid strata (Victorian Invasive Plants). Paterson's curse can invade areas of natural vegetation, particularly where there is frequent disturbance, and can suppress smaller plants (Agriculture Victoria). Plant would invade dry woodlands and grasslands competing with native flora. Has moderate impacts in some less critical habitats. Occurs in disturbed habitats with competition but not noted to crowd out native species (Oregon Noxious Weed Risk Assessments). Based on evidence of native plant displacement this is marked yes.
Reference(s): 
8. Is the plant noted as promoting fire and/or changing fire regimes?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
“…it seeds and dries off in spring leaving little residue.” Little or no change to fire regime (Victorian Invasive Plants). An exhaustive Google/Google Scholar search did not reveal any additional evidence to support this and the question defaults to a “no” answer at this time.
Reference(s): 
9. Is the plant a health risk to humans or animals/fish? Has the species been noted as impacting grazing systems?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Due to a high concentration of pyrrolizidine alkaloids, it is poisonous to grazing livestock, especially those with simple digestive systems, like horses. The toxins are cumulative in the liver, and death results from too much Paterson's curse in the diet. Where introduced it has established and spread successfully in pastures where it can outcompete native species. In Uruguay, it was a browse species eaten mainly by sheep and was regarded as a weedy invader of pastures. Its importance might be on the increase, however, with more recent records of poisoning of cattle in Brazil following ingestion of the weed. In South Africa, it was introduced as a stock feed and spread along roadsides. In the annual pasture-cropping zone in southern Australia, E. plantagineum is a major component of an introduced pasture agro-ecosystem. E. plantagineum competes strongly with more valuable pasture species, especially under light grazing which favours the development of large rosettes, but the high productivity of E. plantagineum can make it a useful forage species. Depending on the rainfall it either dries off in spring leaving little feed for the critical summer/early autumn period or continues to grow vigorously and provide some green feed over summer, especially when heavily grazed, at a time when other species have dried off. Young growth is readily eaten and provides considerable sustenance to stock, whilst older growth is rough and hairy and generally avoided by stock. The plant appears to be eaten readily by sheep, less-readily by cattle and reluctantly by horses, but little data support this so it is possible that differences observed are due, at least partly, to differences in grazing pressure and pasture height. Rosettes contain 6-14% dry matter, 2.0 to 4.8% d.m. nitrogen and are 50 -75% d.m. digestible. Flowering plants contain 20-70% dry matter, 0.5-4.7% d.m. nitrogen and are 37-69% d.m. digestible. Comparisons suggest that E. plantagineum is as nutritious as most recognized pasture species with low dry matter content (20-30%) and relatively high nitrogen content (4.1-4.3%) and digestibility (61-64%) and so should provide useful fodder. The hairiness can cause slavering, dermatitis, inflammation and itching to animals and man. The key problem associated with E. plantagineum, however is that it contains eight hepatotoxic pyrrolizidine alkaloids, particularly echiumine and echimidine, which are at higher levels in rosettes and also vary with soil type, soil fertility and climate. These alkaloids can cause cumulative chronic liver damage and animal mortality, especially if substantial amounts of herbage are eaten over prolonged periods. Monogastric grazing animals such as horses are more susceptible than ruminants because the alkaloids are largely broken down in the rumen. E. plantagineum was considered the primary cause of pyrrolizidine alkaloid poisoning in horses in Australia and toxicity in cattle in Brazil. E. plantagineum is also the major cause of sheep deaths from primary pyrrolizidine alkaloid and associated hepatogenous chronic copper poisoning in New South Wales, particularly in crossbred ewes. Cross-breeds grazing pasture that was up to 61% E. plantagineum had reduced weight and wool growth, but no mortality after 19 months, while the same animals fed solely on fresh E. plantagineum showed some 40% mortality after 16 weeks due to progressive liver damage. The plant has also been implicated in several reported cases of mortality in horses and occasionally young pigs and even caged canaries. Such effects can be minimized if good pasture and livestock management maintains the E. plantagineum percent pasture consumption below 50%. E. plantagineum has been associated with human allergy problems. Use or contamination in foodstuffs can lead to human health risks from the pyrrolizidine alkaloids and threatens bans on contaminated cereal exports from affected areas (CABI). Echium plantagineum contains pyrrolizidine alkaloids and is poisonous. When eaten in large quantities, it causes reduced livestock weight and death, in severe cases. Paterson's curse can kill horses and irritate the udders of dairy cows and the skin of humans. After the 2003 Canberra bushfires a large bloom of the plant occurred on the burned land, and many horses became ill and died from grazing on it. Because the alkaloids can also be found in the nectar of Paterson's curse, the honey made from it should be blended with other honeys to dilute the toxins (EOL). Paterson’s curse (Echium plantagineum ) quickly replaces other more palatable plants in heavily grazed pastures, reducing the value of the pasture and replaces the natural vegetation of the area. Though it is occasionally considered useful in some semi-arid rangeland pastures, it costs Australian graziers approximately $30 million every year in lost production and control costs (Weeds of Australia Biosecurity Queensland Edition).
Reference(s): 
10. Does the plant produce impenetrable thickets, blocking or slowing movement of animals, livestock, or humans?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
A hairy branched biennial up to 50 cm tall (EOL). While the presence of this plant is quite noticeable, there appears to be no evidence that it negatively affects cultural sites, and does not create a physical barrier (Victorian Invasive Plants). An exhaustive Google/Google Scholar search did not reveal any additional evidence to support this, and it is a relatively small annual or short-lived perennial plant unlikely to create recalcitrant physical barriers, and the question defaults to a “no” answer at this time.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Mowed plants regrow and set seed even in very dry soils (Oregon Noxious Weed Risk Assessments). However, this is a non-woody plant, and as such this does not warrant a "yes" answer. Reproduces only by seed (CABI).
Reference(s): 
12. If naturally detached fragments from this plant are capable of producing new plants, is this a common method of reproduction for the plant?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
Reproduces only by seed (CABI). This is also a terrestrial plant that is unlikely to naturally fragment, and acts primarily as an annual. An exhaustive Google/Google Scholar search did not reveal any additional evidence to support this and the question defaults to a “no” answer at this time.
Reference(s): 
13. Does the species (or cultivar or variety) commonly produce viable seed?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
E. plantagineum reproduces only by seed (CABI).
Reference(s): 
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Full-sized, black seeds (or nutlets) take 26 days after pollination to develop at 17°C and 34 to 68 days at 10°C (Piggin and Sheppard, 1995). While four mature seeds could be produced in all flowers, this is never observed. Flowers produce, on average, 37% (max 51%) of potential seeds with a fairly constant percentage between plants at a given site. This percentage declines through the flowering period (Burdon et al., 1988). When damage or cold weather prevents seed production from a series of flowers on a cyme, later flowers immediately compensate producing the full complement of four seeds. Flower number (r²=0.88), total cyme length (r²=0.82), and tap root diameter (r²=0.72) per plant are good predictors of seed production across sites suggesting seed production was not limited by pollination. The weight and number of seeds produced per plant is also directly proportional to the plant straw weight (plant dry weight - seed weight) and therefore reproductive effort (seed weight produced per unit straw weight) is constant for plants of all sizes and there is no threshold size for seed production. Individual plants can produce up to 10,000 seeds. However, in grazed paddocks, plants produce an average of 15-60 (max. 260) seeds. The common abundance of E. plantagineum on roadsides can be related to prolific seeding where grazing pressure is light. Resulting seed rain (seeds produced in a season/m²) varies from 100 (at 0.8 plants/m²) to 12,000 (at 700 plants/m²) in grazed paddocks. Soil seed banks of up to 13,000-18,000 seeds/m² with grazing and of up to 30,000 seeds/m² without grazing have been recorded in Australia, although most populations have between 2000 and 10,000 seeds/m² (CABI).
Reference(s): 
15. Is there significant germination (>25%) of seeds the next growing season, with no requirement of an infrequent environmental condition for seeds to germinate (i.e. fire) or long dormancy period?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
The soil remains parched throughout the Mediterranean summer, and most of the community germinates after the first heavy autumn rains (October-November). Seed germination occurs from 12° to 40°C, favoured by high constant (20° to 30°C) or alternating (15/40°C) temperatures in the presence of moisture; light is not a requirement. This is typical of winter annual species, where spring germination is inhibited by the preceding low winter temperatures. Seeds have an after-ripening period with germination occurring several months after maturity in spring and increasing to 30% by autumn. The remaining seeds germinate at a similar rate per year in subsequent years. The seed coat controls germination; its complete removal allows almost 100% germination. Germination is depressed by a water-soluble inhibitor present in the aerial parts of the plant. Emergence is abundant after rainfall in summer and autumn when temperatures are high, and it is not uncommon for over 50% of seedlings to emerge before the main autumn rains. Cultivation reduces emergence and this is associated with seed burial and reduced soil moisture. E. plantagineum emergence declines with burial depth and does not occur below 8 cm. In the field, most seedlings of E. plantagineum emerge in late summer and early autumn. The seedbank decays at a peak rate of about 35% per annum such that it may last 10 years, but is highly affected by field conditions. Most seedbank losses are through germination. Successful germination is higher in the exotic range due to lower competition from other species for microsites and more seeds make it into the seedbank (CABI).
Reference(s): 
16. Does this plant produce viable seed within the first three years (for an herbaceous species) to five years (for a woody species) after germination?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
E. plantagineum has a winter annual life history strategy (CABI).
Reference(s): 
17. Does this plant continuously produce seed for >3 months each year or does seed production occur more than once a year?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
In California, bloom period is May - July (Calflora). Plants elongate and flower in late winter and early spring in response to increasing photoperiods enhanced by vernalization in winter. This flowering response limits the distribution of the species to warm-temperate and Mediterranean climate regions. Rosettes will flower slightly later if drought stressed. These plants normally die in summer, although those growing near drains, roadsides, rivers and dams, may continue flowering through summer and die in late summer/early autumn. Plants generally flower for 2-5 months. The flowering period is shortened by drought conditions particularly on shallow soil and lengthened if defoliated and if moisture is available. All these factors allow it to be possible to see the odd flowering plant during most of the year (CABI). Flowers Aug - Jan and produces seed Aug - Mar in Victoria, Australia (Agriculture Victoria). In Oregon, nutlets are moderately small and produced in abundance over a long period from spring through late fall as long as insect pollination can occur (Oregon Noxious Weed Risk Assessments). Given the general drought conditions in California, and observations of a 3-month seed production period, this is answered "no" at this time.
Reference(s): 
Dispersal
18. Are the plant’s propagules frequently dispersed long distance (>100 m) by mammals or birds or via domestic animals?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Local spread risk comes from grazing stock that can ingest and pass seed of E. plantagineum. Several species of ant (e.g., Messor sp. in the native range; Pheidole megacephala, Iridomyrmex discors, Prolasius sp. in Australia) collect seeds and store them in granaries above and below the ground, where many later germinate, but ants probably do not transport seed over great distances. The seed can form a significant part of the diet of ground-feeding seed-eating birds (e.g., crested pigeons Ocyphaps lophotes), especially in drought years, and they may be responsible for dispersal over greater distances. The seeds can also pass through the digestive tracts of grazing animals. In addition to ingestion, seeds are often carried on the coats of livestock because the calyx and seed coat of E. plantagineum are rough and adhesive. Wool waste from affected areas can also contain seed of E. plantagineum (CABI).
Reference(s): 
19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
Most seeds fall from the plant at maturity, although the last seed produced per calyx may remain attached. The seeds are relatively small and heavy. Because seeds are relatively heavy they are not spread over any great distance by wind. Seeds are spread by water where plants grow close to rivers and streams or in steep country prone to erosion and run-off (CABI). Long-distance spread via water is not likely frequent, and an exhaustive Google/Google Scholar search did not reveal any additional evidence to support this and the question defaults to a “no” answer at this time.
Reference(s): 
20. Are the plant’s propagules frequently dispersed via contaminated seed (agriculture or wildflower packets), equipment, vehicles, boats or clothing/shoes?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Accidental introductions also occurred through contamination in canary and cumin seed imported into New South Wales from Morocco and France. Another risk of introduction comes from the movement of hay fodder. Movement of soil, fodder, vehicles and livestock has probably caused the greatest spread within and between farms and districts. E. plantagineum seed is sometimes reported as a contaminant of harvested grain because the plant can be a weed in cereal and pasture seed crops. Dispersal may occur by seed movement in soil for road building or construction or in mud attached to all-terrain vehicles. E. plantagineum was almost certainly first exported outside its native range intentionally as a garden species and remains a species of horticultural interest in parts of the world (e.g., USA). E. plantagineum has been noted as a weed in pastures grown for the production of Trifolium subterraneum seed. Seeds of the two species are produced at the same time and are difficult to separate because they are of similar size and colour (CABI). Paterson’s curse has been found in two locations in Oregon. It was first documented in Linn County as a roadside infestation in 2003. Upon investigation, it was concluded that the seeds were introduced as part of a wildflower seed mix (Oregon State University Extension Service).
Reference(s): 
Evaluation Notes
Total PRE Score

  • < 13 : accept (low risk of invasiveness)
  • 13 - 15 : evaluate further
  • > 15 : reject (high risk of invasiveness)

PRE Score: 
19
Number of questions answered: 
20
Screener Confidence (%): 
81.0
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Evaluation visibility: 
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