Plant Assessment Form

Phytolacca americana

Synonyms: Phytolacca decandra L. in part.

Common Names: common pokeweed; American cancer; American pokeweed; cancer jalap; coakum; garget; inkberry; pigeonberry; poke; poke sallet; pokeberry; pokeweed; red-ink plant; redweed; scoke; Virgina poke

Evaluated on: 1/3/07

List committee review date: 13/02/2007

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org
Joseph M. DiTomaso
Univ. California, Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Joe DiTomaso
Peter Warner
Joanna Clines

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 3 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U Reviewed Scientific Publication
Impact?
Four-part score UCCD Total Score
C
1.2 ?Impact on plant community C. Minor Observational
1.3 ?Impact on higher trophic levels C. Minor Other Published Material
1.4 ?Impact on genetic integrity D. None Reviewed Scientific Publication
2.1 ?Role of anthropogenic and natural disturbance in establishment C. Minor Reviewed Scientific Publication
Invasiveness?
Total Points
12 Total Score B
2.2 ?Local rate of spread with no management B. Increases less rapidly Observational
2.3 ?Recent trend in total area infested within state C. Stable Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal C. Low Other Published Material
2.6 ? Potential for natural long-distance dispersal A. Frequent Other Published Material
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
C. Limited Other Published Material
Distribution?
Total Score C
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very low Other Published Material

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? U Reviewed Scientific Publication
Identify ecosystem processes impacted:

Unknown


Sources of information:

Question 1.2 Impact on plant community composition,
structure, and interactions?
C Observational
Identify type of impact or alteration:

Can form dense stands in some locations, but this is relatively rare statewide.


Sources of information:

Tanya Meyer, Yolo County RCD, e-mail 2/23/05.
DiTomaso, observational


Question 1.3 Impact on higher trophic levels? C Other Published Material
Identify type of impact or alteration:

All parts of the plant are toxic to humans and livestock. Birds can become intoxicated from eating the berries. Toxicity unknown in other wildlife.
Widespread infestations in Britain have disrupted bird migration patterns by producing large amounts of food during the migration period.


Sources of information:

DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 3488. Oakland, CA. text here


Question 1.4 Impact on genetic integrity? D Reviewed Scientific Publication

None. No native Phytolacca in California.


Sources of information:

Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA enter text here


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
B Observational
Describe role of disturbance:

Primarily inhabits roadsides and other disturbed places (1)
Disturbing the soil underneath a large plant produces many seedlings (2).


Sources of information:

1. DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 2488. Oakland, CA.
2. Tanya Meyer, Yolo County RCD, e-mail 2/23/05 text here


Question 2.2 Local rate of spread with no management? B Observational
Describe rate of spread:

Populations are expanding, but only locally.


Sources of information:

Tanya Meyer, Yolo County RCD, e-mail 2/23/05 text here


Question 2.3 Recent trend in total area infested within state? C Observational
Describe trend:

Appear to be no more widespread statewide than it was years ago, except for spread in local regions where they are attempting to control it.


Sources of information:

DiTomaso, observational


Question 2.4 Innate reproductive potential? A Reviewed Scientific Publication
Describe key reproductive characteristics:

Perennial. Reproduces by seeds that can live for 40 years in the soil.


Sources of information:

DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 3488. Oakland, CA.
Mitich, L.W. 1994. Common pokeweed. Weed Technology. 8:887-890.


Question 2.5 Potential for human-caused dispersal? C Other Published Material
Identify dispersal mechanisms:

Occasionally cultivated as an ornamental or garden vegetable.


Sources of information:

DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 2488. Oakland, CA. text here


Question 2.6 Potential for natural long-distance dispersal? A Other Published Material
Identify dispersal mechanisms:

Seeds primarily dispersed by birds.


Sources of information:

DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 3488. Oakland, CA. text here


Question 2.7 Other regions invaded? C Other Published Material
Identify other regions:

Native to the Eastern U.S.
Listed as invasive in Belgium (habitats unknown) (1). Also invasive in much of Europe and China, as well as Africa and other parts of eastern Asia.


Sources of information:

(1) Belgian Biodiversity Platform. List of Invasive Species. http://www.biodiversity.be/thematic-forums/invasive-alien-species/species. Accessed 1/3/07


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? C Other Published Material

Throughout California, except deserts and Great Basin to about 1000m. (1)
Invades northern Central Valley riparian areas (2), particularly in the Chico region.


Sources of information:

1. DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 3488. Oakland, CA.
2. Tanya Meyer, Yolo County RCD, e-mail 2/23/05 text here


Question 3.2 Distribution/Peak frequency? D Other Published Material
Describe distribution:

Only occasionally a weed in California. Large stands rarely occur.


Sources of information:

1. DiTomaso, J. M., and E. A. Healy. 2007. Weeds of California and Other Western States. University of California Agriculture and Natural Resources Publication 3488. Oakland, CA


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter No
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually Yes
Seeds remain viable in soil for three or more years Yes
Viable seed produced with both self-pollination and cross-pollination Unknown
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 7
Total unknowns: 1
Total score: A?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrub
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grassland
Great Basin grassland
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forestD, < 5%
riparian woodlandD, < 5%
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): C
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions

  • CA Floristic Province
  • Cascade Range
  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest