PNW 602-E • October 2007 Paterson’s Curse plantagineum in the Pacific Northwest A. Hulting, J. Krenz, and R. Parker

Other common names: Salvation cattle industry approximately and southern coast of Jane, Riverina bluebell, Lady $250 million annually due and in several eastern states. Campbell weed, purple viper’s to pasture land degradation, In addition to pasture lands, bugloss, viper’s bugloss ­associated management costs, oak savanna habitat in western and contamination of wool by Oregon is particularly vulner- Paterson’s curse is a member seeds (see “Australian resourc- able to invasion, as it is similar of the borage family (Boragina- es,” back page). to the native habitat of Pater- ceae). It is native to Mediterra- Paterson’s curse has been son’s curse and may provide an nean and North found in two locations in excellent environment for this but has spread to southern ­Oregon. It was first documented . ­Africa, South and North Ameri- in Linn County as a roadside This weed has the potential ca, , and New Zealand. infestation in 2003 (Figure 1). to severely degrade agricultural Outside of its native habitat, it is Upon investigation, it was con- and native habitats but can still an aggressive, drought-tolerant cluded that the seeds that adapts to many soil were introduced as moisture levels, enabling it to part of a wildflower readily inhabit disturbed areas. seed mix. The weed It is purportedly named after an currently covers a lin- Australian family, the Patersons, ear area of less than who planted it in their garden in 1 acre at that location the 1880s and watched helplessly and is being managed as it took over the landscape. by hand pulling and Pyrrolozidine alkaloids pro- spot applications of duced by Paterson’s curse, simi- herbicide. lar to toxins produced by tansy In 2004, a larger ragwort (Senecio jacobaea), cause site—previously mis- chronic liver damage and some- identified as a related times death when livestock, species—was docu- Figure 1. A Linn County roadside infestation in 2003. ­especially horses and cattle, mented in Douglas graze the continually. County (Figure 2). This weed is a major problem The infested site cov- in Australia, primarily because ers about 300 acres of it excludes beneficial forage spe- hillside pasture, and cies and degrades the quality of Paterson’s curse covers pasture land. Paterson’s curse approximately 100 net is estimated to infest 82 mil- acres. Weeds at this lion acres in Australia and site are being managed costs the Australian sheep and with herbicides. There are no docu- Andrew Hulting, Extension weed mented infestations in specialist, Oregon State Univer- Washington or Idaho, sity; Jennifer Krenz, faculty research but populations do ­assistant, Oregon State University; and exist along the central Figure 2. A large site in Douglas County in 2004. Robert Parker, Extension weed scien- tist, Washington State University

A Pacific Northwest Extension Publication • Oregon • Idaho • Washington be contained and eradicated in can be pink or white. Flow- ­locations mainly by contami- the Pacific Northwest because ers are borne at the tip of each nated wool and fur, hay, equip- of its limited distribution. ­fiddleneck-like inflorescence. ment, and seed, including wild Two of the five pro- bird feed and wildflower seed trude significantly from the mixes. Paterson’s curse can also Description corolla. In contrast, all five be transported via runoff water. stamens of blueweed, a spe- Transport by wind is unlikely Management efforts require cies commonly confused with because the seeds are heavy and early and accurate identifica- Paterson’s curse, protrude from are not wind-borne. tion. Paterson’s curse is an the corolla. erect winter annual or biennial; seeds usually germinate in early Seeds autumn, but can germinate Management throughout the year when envi- Each produces four strategies ronmental conditions are favor- brown or gray “nutlet” seeds, able. Blooming generally starts which are surrounded by a bris- Similar to other invasive spe- in June in Oregon, but flowering tly husk (Figures 6 and 7). An cies, Paterson’s curse seems to plants can be found throughout Australian report states that an thrive in disturbed environ- the year. individual plant can produce ments outside its native range. Paterson’s curse should up to 10,000 seeds, although Paterson’s curse has a deep not be confused with another seed production decreases to taproot, which allows it to take weedy species, , 15 to 250 seeds per plant where advantage of resources, such as most commonly known as blue- grazing occurs. Data from the soil moisture, that other species weed, but also known as viper’s same report suggest that seeds cannot reach. bugloss in some parts of the ­recovered from the soil seed- A study comparing Pater- . bank were still viable after son’s curse populations found 11 years. increased seedling establish- and rosettes ment rates in highly disturbed sites when compared to areas Leaves are alternate, gener- with intact native vegetation ally green to light green, and Habitat (Grigulis et al. 2001). The spe- hairy. Basal and rosette leaves Paterson’s curse grows well cies community composition in range from oval to elongated, in temperate climates with native regions generally is more with distinct lateral veins and cool, wet autumns and springs. diverse than in areas where wavy margins (Figure 3). Basal Its native habitat in Mediter- Paterson’s curse has invaded, leaves may be more upright in ranean Europe is open wood- suggesting that plant competi- dense populations. Rosettes are lands dominated by evergreen tion in its native habitat results approximately 4 to 14 inches oak trees, a habitat similar to in lower establishment rates of in diameter and may resemble western Oregon’s oak savanna Paterson’s curse. those of other rosette-forming habitat. Several studies have found species such as broadleaf plan- Where it has been introduced, that the number of established tain (Plantago major). Leaves on Paterson’s curse is found mostly seedlings in invaded sites the stems are narrow, smaller, in pastures, where it is very ­decreased significantly in the and thinner than rosette leaves. competitive. Best growth occurs absence of grazing. This may on heavier soils, but Paterson’s occur in part because preferen- Stems curse also can be found grow- tial grazing of desirable forage The stems are erect, light ing in sandy soils. Although it is species might create enough green, and hairy. Plants bolt problematic mainly in pastures, space to give Paterson’s curse a in spring and produce one to it also may occur in agricultural competitive advantage. many stems that range from fields and disturbed areas, such Some management guides 8 inches to 6 feet tall (Figure 4). as roadsides. from Australia suggest reduc- ing grazing intensity in the autumn to maintain a vigor- Dispersal ous, competitive pasture plant The flowers have five petals, community during the season are trumpet shaped, and are mechanisms when Paterson’s curse normally approximately 1 inch long Paterson’s curse repro- would establish. However, it is (Figure 5). They are most duces and spreads via seeds. not known whether this man- commonly bluish-purple, but The seeds are spread to new agement strategy would be effective in lowering establish- supplemented with 2,4-D after than the crop or pasture species. ment rates of Paterson’s curse in flowering begins. Contact your Apply the herbicide as soon as the Pacific Northwest. local Extension agent or state Paterson’s curse grows taller In Oregon, prevention, aggres- Department of Agriculture for than the desired forage species. sive containment, and eradica- current herbicide product reg- tion of established populations istration information, product Biological control are currently recommended recommendations, and applica- Natural insect predators may since Paterson’s curse does not tion rates before making any play a role in preventing native infest extensive acreage. herbicide applications. sites from being dominated by Use caution when applying Paterson’s curse. Some of these Prevention and sanitation herbicides, as unintended con- predators have been introduced It is imperative to be attentive sequences can result if herbi- to Australia as biological con- to possible new introductions cides are used inappropriately. trol agents. Paterson’s curse of Paterson’s curse. Pathways If all ground cover is killed has been reported in only a few of seed introduction include ­using a nonselective herbicide, ­locations in the United States, vehicle tires, soil, livestock, wild for example, the loss of vegeta- and biological control agents bird feed, and wildflower seed tion might make the site vul- have not been approved for use mixes. When moving vehicles nerable to invasion by another at this time. or equipment from one field to invasive weed rather than aid another, especially if invasive reestablishment of the native If you suspect a new intro- weeds are present, it is impor- community (Huwer et al. 2004). duction of Paterson’s curse or tant to clean farm equipment, Repeated treatment of a pop- other invasive weed, please con- vehicles, boots, and any surface ulation of Paterson’s curse with tact your local Extension office, that could spread seed. It is also herbicides of the same or similar the state Department of Agricul- crucial to communicate with mode of action could lead to ture, or a contact listed below. neighboring property owners the development of herbicide In Oregon, a sighting report can and other concerned groups and resistance in that population. be submitted online at www. individuals about potential new Instances of herbicide-resistant weedmapper.org/ or by calling populations of Paterson’s curse. populations of Paterson’s curse 1-866-INVADER. The website is have been reported in southern a collaborative effort between Manual removal and western Australia. These several government agencies two areas have reported resis- and Oregon State University. Paterson’s curse is spread tance to the class of herbicides only by seed. Manual removal known as ALS inhibitors, spe- of plants prior to flowering is cifically to chlorsulfuron and recommended for small infesta- metsulfuron. It is important to Photo credits tions. It is important to revisit use herbicides with caution, All photos courtesy of Oregon these infested sites, especially monitor their efficacy, and avoid Department of Agriculture in the spring, to ensure that continual use of the same mode Plant Division-Noxious Weed seedlings are removed before of action. Control, Salem, OR. flowering. In Australia, where Paterson’s curse infests millions of acres, Herbicide use management with herbicides Resources Paterson’s curse currently has is common (see “Australian a limited range in the Pacific resources”). These strategies Online would need to be adapted for Northwest, so there is little Oregon Department of Agricul- Pacific Northwest environmen- information on which herbi- ture (ODA) Plant Division, tal conditions, but they offer cides can be used to effectively Noxious Weed Control. insight as to how to manage manage this weed. In Oregon, www.oregon.gov/ODA/ this plant with herbicides on a glyphosate is used for spot PLANT/WEEDS/profile_ large scale. For instance, wick treating, but sites need to be pcurse.shtml applicator methods have been visited repeatedly because USDA plants database. successful in areas with large glyphosate has no soil residual plants.usda.gov/java/ infestations. In this method, weed control effects. At the profile?symbol=ECPL nonselective herbicides, such Douglas County, OR, site, where Weedmapper. www. as glyphosate, are mixed with Paterson’s curse covers a larger weedmapper.org/ecpl.html area of hillside pasture, piclo- ­water and an adjuvant and ram is used for management, wiped onto weeds that are taller Australian resources Huwer, R.K., D.T. Briese, P.M. Dowling, D.R. Kemp, Department of Agriculture W.M. Lonsdale, D.L. Michalk, and Food, Western Austra- M.J. Neave, A.W. Sheppard, lia. http://agspsrv95.agric. and T.L. Woodburn. 2004. wa.gov.au/dps/version02/ Can an integrated manage- 01_plantviewasp?page= ment approach provide a 6&contentID=48& basis for long-term preven- How to Control Paterson’s tion of weed dominance in Curse. www.agric.wa.gov. Australian pasture systems? au/pls/portal30/docs/ Weed Research 45:175–192. FOLDER/IKMP/PW/ Popay, I. and R. Field. 1996. WEED/DECP/FN2006_ Grazing animals as weed con- PATERSON_CONTROL.PDF trol agents. Weed Technology 10:217–231. Figure 3. Basal and rosette leaves range Print Smyth, M.J., A.W. Sheppard, from oval to elongated and have distinct Allcock, K.G. 2002. Effects of and A. Swirepik. 1997. The lateral veins and wavy margins. phosphorus on growth and effect of grazing on seed pro- competitive interactions of duction in Echium planta- native and introduced species gineum. Weed Research found in White Box wood- 37:63–70. lands. Australian Ecology 27:638–646. Contacts DiTomaso, J.M. and E.A. Healy. Andrew Hulting 2007. Weeds of California and Extension weed specialist other Western States. Univer- Oregon State University sity of California, Agriculture E-mail: andrew.hulting@ and Natural Resources publi- oregonstate.edu cation 3488. Figure 4. Plants bolt in spring and produce Robert Parker one to many stems that range from 8 inches Grigulis, K., A.W. Sheppard, Extension weed scientist to 6 feet tall. J.E. Ash, and R.H. Groves. Washington State University 2001. The comparative E-mail: [email protected] ­demography of the pasture Erickson Weed Herbarium weed University of Idaho ­between its native and invad- Phone: 208-885-7831 ed ranges. Journal of Applied Ecology 38:281–290.

Figure 5. Flowers have five petals, are trumpet shaped, and are approximately 1 inch long.

Figure 6. Each flower produces Figure 7. Seeds of Paterson's four seeds, which are surrounded curse. by a bristly husk.

© 2007 Oregon State University. Published and distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the Oregon State University Extension Ser- vice, Washington State University Extension, University of Idaho Cooperative Extension System, and the U.S. Department of Agriculture ­cooperating. The three participating Extension Services offer educational programs, activities, and materials—without regard to age, color, disability, gender identity or expression, marital status, national origin, race, religion, sex, sexual orientation, or veteran’s status—as required by Title VI of the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, and Section 504 of the Rehabilitation Act of 1973. The Oregon State University Extension Service, Washington State University Extension, and University of Idaho Extension are Equal Opportunity Employers. Published October 2007.