Bloodwort (Achillea millefolium)

Present distribution

Scientific name:	Achillea millefolium L.
Common name(s):	bloodwort, western yarrow

Map showing the present distribution of this weed.

Habitat:

Invasive in much of its range. Occurs in Elm-ash-cottonwood, Douglas-fir, Ponderosa pine, Fir-spruce, Sagebrush, Desert shrub, Chaparral-mountain scrub, Pinyon-juniper, Mountain grasslands, Plains grasslands, Prairie, Wet grasslands, Alpine, open flats, parks, dry meadows, disturbed areas, overgrazed rangelands, replaces more valuable forage species and crops (Aleksoff 1999), sandy, elevated natural levees infrequently flooded in winter (Jansen et al 2005), grassland, woodlands, particularly subalpine (Walsh, Entwistle 1999), turf (UAA 2004), flood irrigated grasslands (Gardi et al 2002). Soils; thin, shallow, infertile, sandy gravely loam (Aleksoff 1999) dry to moist, moderately acid to weakly basic, intermediately fertile, slightly salt-tolerant (DETR 1999), silty well-drained (Biondini et al 1998), wide range of soils, prefers high fertility and dry soils (Bourdôt 1984). Increasing altitude does not appear limit establishment, growth and reproduction (Johnston 2005).

Potential distribution

Potential distribution produced from CLIMATE modelling refined by applying suitable landuse and vegetation type overlays with CMA boundaries

Map Overlays Used

Land Use:
Broadacre cropping; forestry; horticulture perennial; horticulture seasonal; pasture dryland; pasture irrigation

Ecological Vegetation Divisions:
Coastal; heathland; grassy/heathy dry forest; lowland forest; foothills forest; forby forest; damp forest; riparian; wet forest; high altitude shrubland/woodland; alpine treeless; granitic hillslopes; rocky outcrop shrubland; western plains woodland; basalt grassland; alluvial plains grassland; semi-arid woodland; alluvial plains woodland; ironbark/box; riverine woodland/forest; chenopod shrubland; chenopod mallee; hummock-grass mallee; lowan mallee; broombush whipstick

Colours indicate possibility of Achillea millefolium infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	To 1 m (Walsh, Entwistle 1999) and forms “dense patches” [as syn. Achillea tomentosa] (Gildemeister, Brickell 2003) – low nuisance value. Impedes individual access.	ml	mh
2. Reduce tourism?	Can form stands less than 5 square meters (Aleksoff 1999) and grows to 1 m. establishes in native grassland and woodlands (Walsh, Entwistle 1999) – minor effects to aesthetics	ml	m
3. Injurious to people?	As “several thousand achenes may be produced per flowering stem” (Aleksoff 1999), there are large amounts of flowers produced, the pollen of which could cause hay fever – mildly toxic, may cause some physiological issues	ml	m
4. Damage to cultural sites?	“can easily spread in lawns on many types of soil… by rapid branching near the soil surface, the rhizomes can give rise to patches of shoots forming dense covers of leaves, which sometimes crowd out the lawn grasses” (Hakansson 2003) – moderate visual effect on heritage gardens	ml	mh
Abiotic
5. Impact flow?	Terrestrial (Aleksoff) - Little or negligible affect on water flow	l	m
6. Impact water quality?	Terrestrial (Aleksoff) - No noticeable effect on dissolved 0₂OR light levels.	l	m
7. Increase soil erosion?	“Due to its extensive rhizomes [it] is a good soil binder and has been used in erosion control projects” (Aleksoff 1999) – decreases the probability of soil erosion	l	m
8. Reduce biomass?	Although “the weed produced four times as much biomass as the native grass” (Johnston 2005) – it can establish woodlands as well as grasslands (Walsh, Entwistle 1999), therefore biomass may be slightly decreased	mh	mh
9. Change fire regime?	As it is fire resistant (Hulbert 2005) and “not highly flammable” (Aleksoff 1999) and is a “widespread weed of disturbed areas such as roadsides and wasteland, but also established in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999), it is likely to greatly change the frequency and/or intensity of fire risk	h	mh
Community Habitat
10. Impact on composition (a) high value EVC	EVC = Plains Grassy Woodland (E); CMA = Glenelg Hopkins; Bioregion = Dundas Tablelands; VH CLIMATE potential It is “usually present in the earliest stages of vegetation development and persists throughout succession.” Can form pure stand of less than 5 square meters, however usually grows in “a somewhat scattered fashion” and is “tolerant of competition” (Aleksoff 1999). Can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999 – monoculture within a specific layer; displaces all spp. within a strata/layer	h	h
(b) medium value EVC	EVC = Riparian Shrubland (R); CMA = East Gippsland; Bioregion = Highlands – Southern Fall; VH CLIMATE potential It is “usually present in the earliest stages of vegetation development and persists throughout succession.” Can form pure stand of less than 5 square meters, however usually grows in “a somewhat scattered fashion” and is “tolerant of competition” (Aleksoff 1999). Can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999 – monoculture within a specific layer; displaces all spp. within a strata/layer	h	h
(c) low value EVC	EVC = Loamy Sands Mallee (LC); CMA = Mallee; Bioregion = Lowan Mallee; VH CLIMATE potential. It is “usually present in the earliest stages of vegetation development and persists throughout succession.” Can form pure stand of less than 5 square meters, however usually grows in “a somewhat scattered fashion” and is “tolerant of competition” (Aleksoff 1999). Can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999 – monoculture within a specific layer; displaces all spp. within a strata/layer	h	h
11. Impact on structure?	It is “usually present in the earliest stages of vegetation development and persists throughout succession.” Can form pure stand of less than 5 square meters, however usually grows in “a somewhat scattered fashion” and is “tolerant of competition” (Aleksoff 1999). Can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999) – can form monoculture; no other strata/layers present	h	m
12. Effect on threatened flora?	Although it can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999) and can form pure stands (Aleksoff 1999) it has not yet known to impact on Bioregional Priority 1A or VROT spp.	mh	l
Fauna
13. Effect on threatened fauna?	Although it can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999) and can form pure stands (Aleksoff 1999), it would be likely to change habitat, however it has not yet known to impact on Bioregional Priority or VROT spp.	mh	l
14. Effect on non-threatened fauna?	It can establish “in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999) and can form pure stands (Aleksoff 1999) – habitat changed dramatically, leading to the possible extinction of non-threatened fauna	h	m
15. Benefits fauna?	As a food source it is “rated poor in energy and protein content”, however in North America it provides “good” cover for small mammals and small non-game birds (Aleksoff 1999) – provides some assistance in shelter to desirable species	mh	m
16. Injurious to fauna?	“contains volatile oils, alkaloids, and glycosides but is not generally considered a toxic plant because it is so seldom consumed by livestock” (Aleksoff 1999) – mildly toxic, may cause fauna to lose condition	ml	m
Pest Animal
17. Food source to pests?	“Generally unpalatable” (Aleksoff 1999) – provides minimal food for pest animals	l	m
18. Provides harbor?	As it grows to 1 m (Walsh, Entwistle 1999) and can form pure stands, but is reduced back to rosettes in winter (Aleksoff 1999), it has capacity to harbour rabbits or foxes at low densities or as overnight cover	mh	m
Agriculture
19. Impact yield?	A. millefolium “tends to increase rapidly in disturbed areas or overgrazed rangelands, replacing more valuable forage species and crops” and “dominates on overgrazed high summer ranges, where the undisturbed climax vegetation would be made up of wheatgrass.” It is also “rated poor in energy and protein content” (Aleksoff 1999). It “continues to be a problem weed in crops such as beans, field peas, sugar-beet and white clover-seed crops” (Kannangara, Field 1985) and “in New Zealand, barley (Hordeum vulgare) reduced rhizome and seed production” (Aleksoff 1999) due to competition with A. millefolium. “Interferes seriously with the production of some arable crops in the Canterbury, Otago and Southland regions of New Zealand” (Bourdôt 1984) – serious impacts on quantity (>20% reduction)	h	mh
20. Impact quality?	“Contains volatile oils, alkaloids, and glycosides but is not generally considered a toxic plant because it is so seldom consumed by livestock. Milk from cows consuming western yarrow has a disagreeable flavour.” (Aleksoff 1999) – serious impacts on quality – product rejected for sale or export	h	m
21. Affect land value?	“Rhizome production and regeneration greatly increase the difficulty of controlling A. millefolium. Herbicides which can be used on arable land give poor control” (Bourdôt 1984), as a food source for stock it is “rated poor in energy and protein content” (Aleksoff 1999), and is “able to germinate and establish in grass turf [and] colonises open sites” (UAA 2004) – due to the impacts and difficulty to control, land value may be decreased in value <10%	m	mh
22. Change land use?	“It is often and indicator of past overstocking and excessive utilization… tends to decrease on grazing plots once grazing has ceased” (Aleksoff 1999). It is also sensitive to soil cultivation “but produce a slow or weak regrowth in competitive crops after burial by tillage. Many species tolerate the joint effects of competition and annual cutting and can therefore increase on ground where they are able to overcome their weaknesses in early growth.” (Hakansson 2003). “Rhizome production and regeneration greatly increase the difficulty of controlling A. millefolium. Herbicides which can be used on arable land give poor control” (Bourdôt 1984) – may have to change land use to non-grazing and non-tillage uses – may cause a major detrimental change and significant loss for agricultural usage	h	mh
23. Increase harvest costs?	It “continues to be a problem weed in crops such as beans, field peas, sugar-beet and white clover-seed crops” (Kannangara, Field 1985) and “in New Zealand, barley (Hordeum vulgare) reduced rhizome and seed production” (Aleksoff 1999) due to competition with A. millefolium. “Interferes seriously with the production of some arable crops in the Canterbury, Otago and Southland regions of New Zealand” (Bourdôt 1984) – minor increase in cost of harvesting	m	mh
24. Disease host/vector?	Known to attract “beneficial insects” hoverflies, wasps, lady beetles that manage mites and scale (Earnshaw 2004). Aphids Coloradoa achilleae, Uroleucon, and Macrosiphoniella are found on Achillea millefolium (Halbert et al 2000).	m	h

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	Humid, warm conditions are needed for germination (Stevens et al 1993). Also “seeds germinate from no more than a 1 inch depth. They require light for germination and warm temperatures (65-75° F) (UAA 2004). It was also found that rhizome fragments on the soil surface dry out and do not establish, however rhizomes can establish from 5 cm to 30 cm soil depths (Bourdôt 1984). Can germinate in Spring, Summer and Autumn (Johnston 2005) – Requires natural seasonal disturbances such as seasonal rainfall, spring/summer temperatures for germination	mh	mh
2. Establishment requirements?	Although it is “intolerant of dense shade” (Aleksoff 1999), it can tolerate partial shade (DETR 1999) - Can establish under moderate canopy/litter cover	mh	m
3. How much disturbance is required?	“A widespread weed of disturbed areas such as roadsides and wasteland, but also established in native grassland and woodlands, particularly in subalpine areas” (Walsh, Entwistle 1999). “Able to germinate and establish in grass turf [and] colonises open sites” (UAA 2004). Also present in many sites in Kosciuszko National Park “prior to disturbance” (Johnston 2005) – establishes in healthy and undisturbed natural ecosystems	h	mh
Growth/Competitive
4. Life form?	“Rhizomatous herb.” Can come back after fire from the rhizome (Aleksoff 1999) - geophyte	ml	m
5. Allelopathic properties?	Other species grows in the spaces between the plant [As syn. A. tomentosa] (Chatto, Wooster 2000) – no allelopathic properties	l	mh
6. Tolerates herb pressure?	“Generally unpalatable, although domestic livestock and wildlife occasionally consume the flowers” (Aleksoff 1999). Grazing “increased the relative composition” on prairies (Biondini et al 1998) – Favoured by heavy grazing pressure as not eaten by animals/insects and not under a biological control program in Australia/New Zealand.	h	mh
7. Normal growth rate?	Pioneer species (UAA 2004) and showed a high relative growth rate (Loveys et al 2002) - Rapid growth rate that will exceed most other species of the same life form.	h	m
8. Stress tolerance to frost, drought, w/logg, sal. etc?	“The lifecycle of western yarrow in grasslands is completed by the onset of the summer drought and fire season in July. Following fire, regeneration is from rapid rhizome spread and wind dispersal of seeds onto burned sites from adjacent unburned areas” (Aleksoff 1999). “Drought and fire tolerant... can withstand winter temperature -38° F and requires 120 frost free days for development and reproduction. It does not tolerate shade and soil salinity” (UAA 2004). Occurs on a site that withstands “very cold winters” with a frost penetration range of 1.4-2 m (Biondini et al 1998). Slightly salt-tolerant (DETR 1999). Occurs in permanent grasslands - up until recently flood irrigated; currently flood irrigated; and not irrigated in the past 20 years (Gardi et al 2002). Although it is less flood tolerant than Achillea ptarmica, it is a common floodplain species in the Netherlands and occurs in areas that are infrequently flooded (Jansen et al 2005) Highly tolerant to frost, drought and fire. Tolerant to water logging and salinity.	h	mh
Reproduction
9. Reproductive system	“In disturbed soils, fragmented rhizomes regenerate shoots which can emerge from soil depths as great as 12 inches (30 cm). In undisturbed soil the rhizomes remain attached to the parent plant, forming new plants at the rhizome apices.” Produces achenes (Aleksoff 1999) – vegetative and sexual	h	m
10. Number of propagules produced?	“several thousand achenes may be produced per flowering stem” (Aleksoff 1999), approximately 60 000 seeds per plant (Johnston 2005), and “individual plants on cultivated soil may produce about eighty rhizomes during one growing season” (Bourdôt 1984)	h	mh
11. Propagule longevity?	In the soil, seeds at a depth of 32 cm “lost viability slowly over 4 years (Kannangara, Field 1985), however “the viability of freshly shed seeds exceeds 90%. Western yarrow seed showed 41% germination after 9 years in dry storage” (Aleksoff 1999) – Greater than 25% of seeds survive 5-10 years in the soil	ml	mh
12. Reproductive period?	Perennial herb (Bourdôt 1984) – mature plant produces viable propagules for 3 – 10 years	mh	h
13. Time to reproductive maturity?	Although Bender et al (2000) claim that it takes the plant two years to produce seed, Johnston (2005) states that “in temperate conditions vegetative rosettes of A. millefolium plants can form in the first season of growth with some rosettes flowering in the first year. Also, when rhizomes with 1.6 nodes are separated from the parent plant, emergent shoots are produced (Bourdôt 1984) – reaches maturity and produces viable propagules and vegetative propagules become separate individuals, in under a year	h	h
Dispersal
14. Number of mechanisms?	“regenerates from colonization through short-distance (1-2 m) wind dispersal of seeds.” (Aleksoff 1999) “propagules often contaminate commercial seeds and garden throw-outs” (UAA 2004)	mh	m
15. How far do they disperse?	“propagules often contaminate commercial seeds and garden throw-outs” (UAA 2004) – very likely that at least one propagule will disperse greater than one kilometre	h	m

References

Aleksoff K (1999) Achillea millefolium. In: Fire Effects Information System. US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available at http://www.fs.fed.us/database/feis/plants/forb/achmil/all.html (verified 20 November 2008)

Bender MH, Baskin JM, Baskin CC (2000) Age of maturity and life span in herbaceous polycarpic perennials. The Botanical Review 66(3), 311-349

Biondini ME, Patton BD, Nyren PE (1998) Grazing intensity and ecosystem processes in a northern mixed-grass prairie, USA. Ecological Applications 8(2), 469-479

Bourdôt GW (1984) Regeneration of yarrow (Achillea millefolium L.) rhizome fragments of different length from various depths in the soil. Weed Research 24, 421-429

Chatto B, Wooster S (2000) Beth Chatto’s gravel gardens: Drought resistant Planting Through the Year. Frances Lincoln ltd, UK.

Department of the Environment, Transport and Regions, UK (DETR) (1999) ECOFACT. DETR under licence from the Controller of Her Majesty’s Stationary Office. Available at http://www.ceh.ac.uk/products/publications/documents/ECOFACT2a.pdf (verified 18 November 2008)

Earnshaw S (2004) Hedgrows for California Agriculture; A resource guide. Community Alliance with Family Farmers. Available at
http://www.caff.org/programs/farmscaping/Hedgerow.pdf (verified 3 December 2008)

Gardi C, Tomaselli M, Parisi V, Petraglia A, Santini C (2002) Soil quality indicators and biodiversity in northern Italian permanent grasslands. European Journal of Soil Biology 38, 130-110

Gildemeister H, Brickell C (2003) Mediterranean Gardening: A Waterwise Approach. University of California Press.

Hakansson S (2003) Weeds and weed management on arable land: An ecological approach. CABI Publishing.

Halbert SE, Remaudiere G, Webb SE (2000) Newly established and rarely collected aphids (Homoptera: Aphidadae) in Florida and the southeastern United States. Florida Entomologist 83(1), 79-91. Available at http://www.fcla.edu/FlaEnt/fe83p79.pdf (verified 3 December 2008)

Hulbert JH (2005) Community Wildfire Protection Plan for the Cascade Locks. White Salmon, USA. Available at
https://scholarsbank.uoregon.edu/xmlui/bitstream/handle/1794/6490/Cascade_Locks_CWPP.pdf;jsessionid=8AC6E9C2DA8CCB87442F26CFBED65FAF?sequence=1 (verified 20 November 2008)

Jansen C, Van de Steeg HM, de Kroon H (2005) Investigating a trade-off in root morphological responses to a heterogeneous nutrient supply and to flooding. Functional Ecology 19, 952-960

Johnson FM http://www4.gu.edu.au:8080/adt-root/uploads/approved/adt-QGU20070105.164954/public/02Whole.pdf

Kannangara HW, Field RJ (1985) Environmental and physiological factors affecting the fate of seeds of yarrow (Achillea millefolium L.) in arable land in New Zealand. Weed Research 25, 87-92

Knopf J (1991) The xeriscape flower garden: A waterwise guide for the Rocky Mountain Region. Big Earth Publishing.

Loveys BR, Scheurwater I, Pons TL, Fitter AH, Atkin OK (2002) Growth temperature influences the underlying components of relative growth rate: an investigation using
inherently fast- and slow-growing plant species. Plant, Cell and Environment 25, 975-987

Stevens S, Stevens AB, Gast KLB, O’Mara JA, Tisserat N, Bauernfeind R (1993) Commercial speciality cut flower production; Achillea (yarrows). Kansas State University, Manhattan, Kansas. Available at http://www.oznet.ksu.edu/library/hort2/mf1069.pdf (verified 16 July 2008)

University of Alaska Anchorage (UAA) (2005) Non native plant species of Alaska; Sneezewort. Available at http://akweeds.uaa.alaska.edu/pdfs/species_bios_pdfs/Species_bios_ACPT.pdf (verified 15 July 2008)

University of Alaska Anchorage (UAA) (2004) Non native plant species of Alaska; Common Yarrow. Available at http://akweeds.uaa.alaska.edu/pdfs/species_bios_pdfs/Species_bios_ACMIM.pdf (verified 20 November 2008)

Walsh NG, Entwistle TJ (eds) (1999) Flora of Victoria. Vol 4, Dicotyledons; Carnaceae to Asteraceae. Inkata Press, Melbourne.

Global present distribution data references

Australian National Herbarium (ANH) (2008) Australia’s Virtual Herbarium, Australian National Herbarium, Centre for Plant Diversity and Research, Available at
http://www.anbg.gov.au/avh/ (verified 2/12/08).

Global Biodiversity Information Facility (GBIF) (2008) Global biodiversity information facility, Available at http://www.gbif.org/ (verified 2/12/08)

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