Asclepias syriaca L

EPPO training course 08-11/07/2013 -Belgrade, SR
The EPPO Prioritization Process for
Asclepias syriaca L.
for Vojvodina, autonomous province of Serbia

Taxonomic position:
Magnoliopsida, Asclepidiaceae
Synonyms (www.cabi.org):
Asclepias cornuti Decne
Asclepias intermedia Vail.
Asclepias kansana Vail.
Asclepias syriaca L. var. kansana
(Vail) Palmer & Steyerm
Asclepias tomentosum Opiz
Common name (EN): Common
milweed
EPPO code: ASCSY

A.1 - Is the plant species known to be alien in the area
under assessment?
Yes
Asclepias syriaca is native to North America
and some areas of Canada
Distribution of Asclepias
syriaca in the USA and
Canada

A.2 - Is the plant species established in at least a part of
the area under assessment?
Yes
According to Vrbničanin et al. (2008) plant is established in
Bačka (west area of Vojvodina), and north part of Banat (east
area of Vojvodina).

A.5 - How high is the spread potential of the plant in the
area under assessment?
High
Level of uncertainty: low
Seeds are spread by traffic vehicles, by the wind, which
catches the fluffy part and carries the seed for long distances.
Plant can spread quickly underground as well, by rhizomes.
Parts of the rhizome is spread by human activities like
movement of soils, or dispersed by farm machinery. Asclepias
syriaca occurs along the ponds and waterways, so there is
possibility to spread by water (Wyatt et al. 1996; Wyatt et al.
1993).

A.6 - How high is the potential negative impact of the
plant on native species, habitats and ecosystems in the
area under assessment?
Medium
Level of uncertainty: low
Asclepias syriaca can be found
along roadsides, railways, along
the banks and flood plains of
lakes, where it forms large,
dense, persistent populations,
but it is not high competitor,
especially for light and soil
resources like water and
nutrients (Evetts and Burnside
1975).

A.7 - How high is the potential negative impact of the plant
on agriculture, horticulture or forestry in the area under
assessment?
High
Level of uncertainty: low
In the region of Vojvodina, Asclepias syriaca is less common in
arable areas, but in the Subotica-Horgoš sands (north part of
Vojvodina) plant was identified in both reclaimed and
abandoned orchards and vineyards on sandy terrain and the
arable land in the crop of spring barley, sunflower and rapeseed
which has made tremendous damage (Dolmagić, 2010).

A.8 - How high are the potential additional impacts (e.g.
on animal and human health, on infrastructures, on
recreational activities, other trade related impacts such
as market losses)?
High
Level of uncertainty: low
The entire plant is considered
poisonous. Turkey, chickens, sheep,
goats, cattle, and horses are susceptible
to milkweed toxins. Humans can also be
poisoned by the plants. Asclepias
syriaca is also allergenic weed species
and their milky sap can cause contact
dermatitis to people with sensitive skin
(Konstantinović et al. 2009; Anderson
1999).

According to the ratings provided, the assessed
species falls into the:
- List of invasive alien plants

B.1 - Is the plant species internationally traded or are
there other existing or potential international pathways?
Yes
Asclepias syriaca flower is a good source of honey for bees
(Bhowmik and Bandeen, 1976), and it is believed that
beekeepers are doing uncontrolled trade of seeds from
neighbouring countries.

B.2 - Is the risk of introduction by these international
pathways identified to be superior to natural spread?
Yes
International trade of Asclepias syriaca seeds and its
deliberate seeding by beekeepers is more influential on
species spread than natural one, because plat species is
not high competitor.
B.3 - Does the plant species still have a significant area
suitable for further spread in the area under assessment?
Small area suitable for further spread
Research result of Asclepias syriaca distribution in Vojvodina
(Vrbničanin et al. 2008), show that more than 40% of the
potential suitable area is already occupied.

Outcome of the second part:
A PRA is not considered a priority.

References
• Anderson,W.P. (1999) Perennial Weeds: Characteristics and identifications of selected herbaceous species. Iowa State University
Press.
• Bhowmik, P.C., Bandeen, J.D. (1976) The biology of Canadian weeds. 19. Asclepias syriaca L. Can. J. Plant Sci. 56, 579-589.
• Dolmagić, A. (2010) Preliminarna ispitivanja o mogućnosti suzbijanja ciganskog perja (Asclepias syriaca L.) - u usevu soje, Biljni lekar,
38, 1, 42-49.
• Evetts, L. (1977) Common milkweed--the problem. Proc. Annu. Meet. North. Cent. Weed Contr. Conf. 32:96-99.
• Evetts, L. L. and O. C. Burnside. (1975) Effect of early competition on growth of common milkweed. Weed Science journal. 23, 1-3.
• Igić, R., Boža, P., Anačkov, G., Vukov, D., Polić, D., Borišev, M. (2003) Asclepias syriaca L. (cigansko perje) u flori Vojvodine. Zbornik
radova Prirodno-matematičkog fakulteta, serija za biologiju, Novi Sad, 31-32, 26-32.
• Konstantinović B., Meseldžija ., Konstantinvić, Bo., Mandić, N ., Korać, M. (2009) Allergenic weed species and possibilities of their
control. Biljni lekar, 37,6,634-640.
• Reed, C.F. (1970) Selected weeds of the United States. Ag. Handbook 366. USDA, Washington, DC.
• Stanković-Kalezić, R., Radivojević, Lj., Jovanović, V., Janjić, V., Šantrić, Lj. (2008) Adventivna vrsta Asclepias syriaca L. na području
Pančevačkog rita. Acta herbologica 17,1, 95-103.
• Tutin, T.G., Heywood, V.H., Burges, N.A., Moore, D.M., Valentine, D.H., Walters, S.M., Webb, D.A. (1972) Flora Europaea III.
Cambridge University Press, Cambridge.
• Vrbničanin, S., Malidža, G., Stefanović, L., Elezović, I., Stanković-Kalezić, R., Marisavljević, D, Radovanov-Jovanović, K., Pavlović, D.,
Gavrić, M. (2008) Distribucija nekih ekonomski štetnih, invazivnih i karantinskih korovskih vrsta na području Srbije. Biljni lekar 5, 303-
313.
• Wyatt, R., (1996) More on the southward spread of common milkweed, Asclepias syriaca L. Bulletin of the Torrey Botanical Club 123,
68–69.
• Wyatt, R., Stoneburner A., Broyles, S.B. and Allison, J.R. (1993) Range Extension Southward in Common Milkweed, Asclepias syriaca
L.Bulletin of the Torrey Botanical Club 120,2, 177-179.
• Yenish, P.J., A. Fry, T.A., Durgan B.R. and Wyse, D.L. (1996) Tillage Effects on Seed Distribution and Common Milkweed (Asclepias
syriaca) Establishment. Weed Science 44, 4, 815-820.