Pacific Island Ecosystems at Risk (PIER)


Persicaria chinensis


RISK ASSESSMENT RESULTS: High risk, score: 14


Australian/New Zealand Weed Risk Assessment adapted for Hawai‘i.
Information on Risk Assessments
Original risk assessment

Persicaria chinensis (L.) H. Gross, Bot. Jahrb. Family - Polygonaceae. Common Names(s) - Chinese knotweed, mountain knotweed, huo tan mu. Synonym(s) - Polygonum chinense L. (basionym).

Answer

Score

1.01

Is the species highly domesticated?

y=-3, n=0

n

0

1.02

Has the species become naturalized where grown?

y=1, n=-1

1.03

Does the species have weedy races?

y=-1, n=-1

2.01

Species suited to tropical or subtropical climate(s) (0-low; 1-intermediate; 2-high) – If island is primarily wet habitat, then substitute “wet tropical” for “tropical or subtropical”

See Append 2

2

2.02

Quality of climate match data (0-low; 1-intermediate; 2-high) see appendix 2

2

2.03

Broad climate suitability (environmental versatility)

y=1, n=0

y

1

2.04

Native or naturalized in regions with tropical or subtropical climates

y=1, n=0

y

1

2.05

Does the species have a history of repeated introductions outside its natural range?

y=-2, ?=-1, n=0

n

3.01

Naturalized beyond native range y = 1*multiplier (see Append 2), n= question 2.05

y

2

3.02

Garden/amenity/disturbance weed y = 1*multiplier (see Append 2)

n=0

3.03

Agricultural/forestry/horticultural weed y = 2*multiplier (see Append 2)

n=0

y

4

3.04

Environmental weed y = 2*multiplier (see Append 2)

n=0

n

3.05

Congeneric weed y = 1*multiplier (see Append 2)

n=0

y

2

4.01

Produces spines, thorns or burrs

y=1, n=0

n

0

4.02

Allelopathic

y=1, n=0

4.03

Parasitic

y=1, n=0

n

0

4.04

Unpalatable to grazing animals

y=1, n=-1

y

1

4.05

Toxic to animals

y=1, n=0

n

0

4.06

Host for recognized pests and pathogens

y=1, n=0

n

0

4.07

Causes allergies or is otherwise toxic to humans

y=1, n=0

n

0

4.08

Creates a fire hazard in natural ecosystems

y=1, n=0

4.09

Is a shade tolerant plant at some stage of its life cycle

y=1, n=0

4.10

Tolerates a wide range of soil conditions (or limestone conditions if not a volcanic island)

y=1, n=0

4.11

Climbing or smothering growth habit

y=1, n=0

y

1

4.12

Forms dense thickets

y=1, n=0

5.01

Aquatic

y=5, n=0

n

0

5.02

Grass

y=1, n=0

n

0

5.03

Nitrogen fixing woody plant

y=1, n=0

n

0

5.04

Geophyte (herbaceous with underground storage organs -- bulbs, corms, or tubers)

y=1, n=0

n

0

6.01

Evidence of substantial reproductive failure in native habitat

y=1, n=0

n

0

6.02

Produces viable seed.

y=1, n=-1

y

1

6.03

Hybridizes naturally

y=1, n=-1

6.04

Self-compatible or apomictic

y=1, n=-1

6.05

Requires specialist pollinators

y=-1, n=0

n

0

6.06

Reproduction by vegetative fragmentation

y=1, n=-1

6.07

Minimum generative time (years) 1 year = 1, 2 or 3 years = 0, 4+ years = -1

See left

7.01

Propagules likely to be dispersed unintentionally (plants growing in heavily trafficked areas)

y=1, n=-1

y

1

7.02

Propagules dispersed intentionally by people

y=1, n=-1

y

1

7.03

Propagules likely to disperse as a produce contaminant

y=1, n=-1

y

1

7.04

Propagules adapted to wind dispersal

y=1, n=-1

n

-1

7.05

Propagules water dispersed

y=1, n=-1

n

-1

7.06

Propagules bird dispersed

y=1, n=-1

y

1

7.07

Propagules dispersed by other animals (externally)

y=1, n=-1

n

-1

7.08

Propagules survive passage through the gut

y=1, n=-1

y

1

8.01

Prolific seed production (>1000/m2)

y=1, n=-1

8.02

Evidence that a persistent propagule bank is formed (>1 yr)

y=1, n=-1

8.03

Well controlled by herbicides

y=-1, n=1

y

-1

8.04

Tolerates, or benefits from, mutilation, cultivation, or fire

y=1, n=-1

8.05

Effective natural enemies present locally (e.g. introduced biocontrol agents)

y=-1, n=1

Total score:

14

Supporting data:

Notes

Source

1.01

No evidence.

 

1.02

1.03

2.01

(1) Native to China, Japan, Korea, Taiwan, Bhutan, India, Nepal, Sri Lanka, Myanmar, Thailand, Indonesia, Malaysia, Philippines.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?416899 [Cited 2009 April 3].

2.02

(1) Native to China, Japan, Korea, Taiwan, Bhutan, India, Nepal, Sri Lanka, Myanmar, Thailand, Indonesia, Malaysia, Philippines.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?416899 [Cited 2009 April 3].

2.03

(1) Common in brush wood, forest borders, open forest and riverbanks from 250- 3300 m in altitude. (2) Wet valleys, grassy slopes, mixed forests, thickets in valleys, mountain slopes: sea level to 3000 m.

(1) vanValenburg J.L., Bunyapraphatsara, N. (Editors). 2002. Plant Resources of South East Asia 12 (2) Medicinal and Poisonous Plants 2. Prosea Foundation. Bogor, Indonesia. 782 pp. (2) http://www.efloras.org/florataxon.aspx?flora_id=610&taxon_id=200006718 [Cited 2009 April 15].

2.04

(1) Native to China, Japan, Korea, Taiwan, Bhutan, India, Nepal, Sri Lanka, Myanmar, Thailand, Indonesia, Malaysia, Philippines.

(1) http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?416899 [Cited 2009 April 3].

2.05

No evidence of repeated introductions.

 

3.01

(1) Naturalized sparingly in Hawaii in agricultural lands and disturbed areas.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

3.02

(1) Naturalized sparingly in Hawaii in agricultural lands and disturbed areas. [see 3.03 instead]

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

3.03

(1) Naturalized sparingly in Hawaii in agricultural lands and disturbed areas. (2) Weed of tea crops in India.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press. (2) Rao V.S., Rahman F., Singh H.S., Dutta A.K., Saikia M.C., Sharma S.N., Phukan B.C. 1976. Effective weed control in tea by glyphosate. Indian Journal of Weed Science. 8 (1):1-14.

3.04

(1) Naturalized sparingly in Hawaii in agricultural lands and disturbed areas. (2) Weed of tea crops in India.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press. (2) Rao V.S., Rahman F., Singh H.S., Dutta A.K., Saikia M.C., Sharma S.N., Phukan B.C. 1976. Effective weed control in tea by glyphosate. Indian Journal of Weed Science. 8 (1):1-14.

3.05

(1) Persicaria perfoliata is an invasive weed in Connecticut, Delaware, Massachusetts, Maryland, New Jersey, New York, Pennsylvania, Virginia, West Virginia, Washington DC and in nine eastern national parks.

(1) http://www.nps.gov/plants/ALIEN/fact/pepe1.htm [Cited 2009 April 15].

4.01

(1) No spines, thorns or burrs.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

4.02

Unknown

4.03

(1) Not parasitic.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

4.04

(1) Not palatable.

(1) Paulsamy S., Bon-Seop K., Arumugasamy K., Padmathy S. 2003. Strategy to control surface fire using vegetational fire breaks in rangelands of Nilgris, Southern India. Korean Journal of Ecology. 26 (5):251-254.

4.05

(1) No evidence of toxicity found in Toxnet. (2) No evidence in Pub Med.

(1) http://toxnet.nlm.nih.gov/cgi-bin/sis/search [Cited 2009 April 16]. (2) http://www.ncbi.nlm.nih.gov/sites/entrez [Cited 2009 April].

4.06

No evidence(1) In India, Persicaria chinensis was found to be a host for Colletotrichum capsici.

(1) Ali M.S., Saikia U.N. 1991. New host records. Indian Phytopathology. 44 (4):558-559.

4.07

(1) Polygonum chinensis is used in its entirety as a folk medicine in Taiwan to treat many infectious diseases. (2) Some clans of the Meetei in North East India eat Persicaria chinensis. (3) Used for eye diseases and as a poultice for stomachaches in India. The decoction is used for depurative in Vietnam.

(1) Tsai P-L, Wang J-P, Chang C-W, Kuo S-C, Lee Chao P-D. 1998. Constituents and Bioactive Principles of Polygonum chinensis. Phytochemistry 9(6):1663-1666. (2) http://www.eubios.info/ABC4/abc4320.htm [Cited 2009 April 3] .(3) vanValenburg J.L., Bunyapraphatsara, N. (Editors). 2002. Plant Resources of South East Asia 12 (2) Medicinal and Poisonous Plants 2. Prosea Foundation. Bogor, Indonesia. 782 pp.

4.08

Unknown

4.09

Unknown

4.10

Unknown

4.11

(1) Perennial herbs or subshrubs. (2) Diffuse woody herb that grows scrambling over shrubs.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press. (2) Reddy N.P., Bahadur B., Kumar P.V. 1977. Heterostyly in Polygonum chinense L. Journal of Genetics. 63 (2):79-82.

4.12

Unknown

5.01

(1) Terrestrial, perennial herbs or subshrubs.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

5.02

(1) Polygonaceae.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

5.03

(1) Polygonaceae.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

5.04

(1) Perennial herbs or subshrubs.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

6.01

(1) Widely distributed in subtropical regions of India to East and Southeast Asia.

(1) vanValenburg J.L., Bunyapraphatsara, N. (Editors). 2002. Plant Resources of South East Asia 12 (2) Medicinal and Poisonous Plants 2. Prosea Foundation. Bogor, Indonesia. 782 pp.

6.02

(1) Propagated by seeds.

(1) http://books.google.com/books?id=klAFeYz4YdYC&pg=RA1-PA354&lpg=RA1-PA354&dq=polygonum+chinense&source=bl&ots=QiNMaQNqQE&sig=
nomzmKFbjr1ComAtJ3YlsUf4tAM&hl=en&ei=2JznSYb2H5z8tgO0g-XoAQ&sa=X&oi=book_result&ct=result&resnum=10 [Cited 2009 April 16].

6.03

Unknown(1) This study used a low-copy nuclear gene region (LEAFY second intron) we show multiple instances of allopolyploid speciation in Persicaria (Polygonaceae), which includes many important weeds. Our molecular phylogenetic study of Persicaria, focused on Eupersicaria (or Persicaria sect. Persicaria), and suggested many cases of allopolyploid speciation on the basis of significant incongruence between cpDNA and nrITS trees. This revealed substantial reticulation in Eupersicaria, such incongruence only identified hybrids when nrITS has been homogenized to the paternal lineage.

(1) Kim S.T., Sultan S.E., Donoghue M.J. 2008. Allopolyploid speciation in Persicaria (Polygonaceae): Insights from a low-copy nuclear region. PNAS. 105:12370-12375.

6.04

Unknown (1) The flowers are heterostylous; pin-eyed (exerted style and low stamens) and thrum-eyed (exerted stamens and low style), flowers are borne on different plants. The position of stamens and styles in both types of flower forms is complementary suggesting that this arrangement favors cross pollination leading to out-breeding populations. Experiments to test the self and cross compatibility were not done. (2) Persicaria perfoliata is primarily a self-pollinating plant.

(1) Reddy N.P., Bahadur B., Kumar P.V. 1977. Heterostyly in Polygonum chinense L. Journal of Genetics. 63 (2):79-82. (2) http://www.nps.gov/plants/ALIEN/fact/pepe1.htm [Cited 2009 April 15].

6.05

(1) Entomophilous (2) Persicaria maculosa is self-compatible and pollinated by insects.

(1) http://florabase.calm.wa.gov.au/browse/profile/21343 [Cited 2009 April 16]. (2) http://florabase.calm.wa.gov.au/browse/profile/21343 [Cited 2009 April 16].

6.06

Unknown

6.07

Unknown (1) Perennial herbs or subshrubs.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press.

7.01

(1) Naturalized sparingly in Hawaii in agricultural lands and disturbed areas. (2) Weed of tea crops in India.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press. (2) Rao V.S., Rahman F., Singh H.S., Dutta A.K., Saikia M.C., Sharma S.N., Phukan B.C. 1976. Effective weed control in tea by glyphosate. Indian Journal of Weed Science. 8 (1):1-14.

7.02

(1) Polygonum chinensis is used in its entirety as a folk medicine in Taiwan to treat many infectious diseases. (2) Some clans of the Meetei in North East India eat Persicaria chinensis. (3) Used for eye diseases and as a poultice for stomachaches in India. The decoction is used for depurative in Vietnam.

(1) Tsai P-L, Wang J-P, Chang C-W, Kuo S-C, Lee Chao P-D. 1998. Constituents and Bioactive Principles of Polygonum chinensis. Phytochemistry 9(6):1663-1666. (2) http://www.eubios.info/ABC4/abc4320.htm [Cited 2009 April 3] .(3) vanValenburg J.L., Bunyapraphatsara, N. (Editors). 2002. Plant Resources of South East Asia 12 (2) Medicinal and Poisonous Plants 2. Prosea Foundation. Bogor, Indonesia. 782 pp.

7.03

(1) Naturalized sparingly in Hawaii in agricultural lands and disturbed areas. (2) Weed of tea crops in India.

(1) Wagner, W.L., Herbst, D.R., Sohmer, S.H., Manual of the Flowering Plants of Hawaii. Vol. 2. 1990, Honolulu: Bishop Museum Press. (2) Rao V.S., Rahman F., Singh H.S., Dutta A.K., Saikia M.C., Sharma S.N., Phukan B.C. 1976. Effective weed control in tea by glyphosate. Indian Journal of Weed Science. 8 (1):1-14.

7.04

No adaptation for wind dispersal. (1) Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm. (2) Fruit is 3-sided black pulpy nut 1 cm long.

(1) http://www.efloras.org/florataxon.aspx?flora_id=610&taxon_id=200006718 [Cited 2009 April 9]. (2) Barnes, D.E., Chan L.G. 1990. Common Weeds of Malaysia and Their Control. Ancon Berhad Persearan Selangor. Shah Alan, Malaysia.

7.05

No adaptation for water dispersal. (1) Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm. (2) Fruit is 3-sided black pulpy nut 1 cm long.

(1) http://www.efloras.org/florataxon.aspx?flora_id=610&taxon_id=200006718 [Cited 2009 April 9]. (2) Barnes, D.E., Chan L.G. 1990. Common Weeds of Malaysia and Their Control. Ancon Berhad Persearan Selangor. Shah Alan, Malaysia.

7.06

(1) Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm. (2) Fruit is 3-sided black pulpy nut 1 cm long. (3) Seeds of Persicaria chinensis were dispersed by yellow-vented bulbuls and Sooty-headed bulbuls in a shrubland of Java Indonesia.

(1) http://www.efloras.org/florataxon.aspx?flora_id=610&taxon_id=200006718 [Cited 2009 April 9]. (2) Barnes, D.E., Chan L.G. 1990. Common Weeds of Malaysia and Their Control. Ancon Berhad Persearan Selangor. Shah Alan, Malaysia. (3) Partasasmita R. and K. Ueda. 2005. The role of bulbuls as seed dispersal agents in a tropical shrubland of Java, Indonesia. In: Fourth International Symposium/Workshop on Frugivores and Seed Dispersal. Theory and its Application in a Changing World. July 9-16 2005. Brisbane, Australia.

7.07

No external means of attachment. (1) Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm.

(1) http://www.efloras.org/florataxon.aspx?flora_id=610&taxon_id=200006718 [Cited 2009 April 9].

7.08

(1) Achenes included in persistent perianth, black, opaque, broadly ovoid, trigonous, 3-4 mm. (2) Fruit is 3-sided black pulpy nut 1 cm long.

(1) http://www.efloras.org/florataxon.aspx?flora_id=610&taxon_id=200006718 [Cited 2009 April 9]. (2) Barnes, D.E., Chan L.G. 1990. Common Weeds of Malaysia and Their Control. Ancon Berhad Persearan Selangor. Shah Alan, Malaysia.

8.01

Unknown

8.02

Unknown (1) Persicaria perfoliata has a seedbank that persists over 7 years with staggered germination of the seeds [related species with long-lived seed bank]

(1) http://www.nps.gov/plants/ALIEN/fact/pepe1.htm [Cited 2009 April 15].

8.03

(1) Effective control based on 18 litre spray solution of Dasatox F at 160 ml. and Paraquat at 60 ml. or Ancom 2, 4-D Na salt at 80g. (2) Glyphosate controlled perennial grass weeds such as Imperata cylindrica, Paspalum conjugatum, Paspalum scrobiculatum, Arundinella bengalensis and Setaria palmifolia at rates ranging from 0.4 to 2.4 kg/ha. It was also effective against broad-leaved weeds such as Borreria hispida, Polygonum chinense and Commelina benghalensis. The addition of Triton AE, a wetting and sticking agent, had no effect on glyphosate activity but reduced rainwash 1-2 h after herbicide application. Ammonium sulphate at up to 6 kg/ha enhanced the rate of glyphosate activity. 2,4-D as a tank mixture with glyphosate enhanced the activity of the latter. This synergistic effect helped reduce the rate of glyphosate substantially. Also, in a mixed weed population, 2,4-D can control most broad-leaved weeds and glyphosate can eliminate persistent grass weeds and some broad-leaved species.

(1) Barnes, D.E., Chan L.G. 1990. Common Weeds of Malaysia and Their Control. Ancon Berhad Persearan Selangor. Shah Alan, Malaysia. (2) Rao, V. S., F. Rahman, et al. (1976). "Effective weed control in tea by glyphosate." Indian Journal of Weed Science 8(1): 1-14.

8.04

Unknown

8.05

Unknown


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