Plant Assessment Form

Ludwigia peploides

Synonyms: Jussiaea peploides

Common Names: floating water primrose; California waterprimrose

Evaluated on: 3/1/04

List committee review date: 19/03/2004

Re-evaluation date:

Evaluator(s)

Joel Trumbo
CA Dept of Fish and Game
1701 Nimbus Road, Suite F, Rancho Cordova, CA 95670
(916) 358-2952
jtrumbo@ospr.dfg.ca.gov
Joe DiTomaso
UC Davis
Weed Science Program, Robbins Hall, Univ. California, Davis CA 95616
530-754-8715
DiTomaso@vegmail.ucdavis.edu

List commitee members

Carla Bossard
Joe DiTomaso
John Randall
Cynthia Roye
Jake Sigg
Alison Stanton
Peter Warner

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? High
Alert Status? No Alert
Documentation? 2.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes A Observational
Impact?
Four-part score AABD Total Score
A
1.2 ?Impact on plant community A. Severe Observational
1.3 ?Impact on higher trophic levels B. Moderate Other Published Material
1.4 ?Impact on genetic integrity D. None Reviewed Scientific Publication
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
Invasiveness?
Total Points
15 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 B. Increasing less rapidly Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal B. Moderate Observational
2.6 ? Potential for natural long-distance dispersal A. Frequent Observational
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
C. Limited Observational
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
B. Moderate Observational

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? A Observational
Identify ecosystem processes impacted:

increased sedimentation, increased organic enrichment, restricted water flow and decreased light availability into the water column. Changes in dissolved oxygen concentrations may also be expected to occur in non-flowing systems with dense infestations. described impacts would be expected from any infestation of floating species with heavy biomass above and below the water surface


Sources of information:

personal observation, Joel Trumbo Butte County 1990 - present. jtrumbo@ospr.dfg.ca.gov


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

severe impacts would include occlusion (>75%) of water surface limiting the growth of native species within the water column or on water surface. Fragmentation of native aquatic plant community . described impacts would be expected from any aquatic plant infestation which forms, large, monotypic vegetation mats. Coverage of water surface is often complete in shallow water bodies.


Sources of information:

personal observation, Joel Trumbo Butte County 1990 - present. jtrumbo@ospr.dfg.ca.gov


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

dense infestations of emersed aquatic vegetation can cause alteration of aquatic faunal communities due to changes in subsurface cover and dissolved oxygen content. dense aquatic weed cover will change subsurface habitat quality for fish species because of increased biomass.


Sources of information:

Aquatic vgetation influences on growth and recruitement of age-0 largemouth bass in Aliceville Lake. Alabama Department of Conservation and Natural Resources, January 1996.


Question 1.4 Impact on genetic integrity? D Reviewed Scientific Publication

While several subspecies exist within CA (native and introduced), there appears to be no evidence of hybridization sexual reproduction may be limited.


Sources of information:

Aquatic and Riparian Weeds of the West. Joe DiTomaso and Evelyn Healy. University of California Agriculture and Natural Resources. Oakland, California. 2003.


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

Species appears to cause most of its problems in man-made structures such as irrigation and drainage canals. In natural areas, problems are often related to human-caused nutrient enrichment.


Sources of information:

personal observation, Joel Trumbo Butte County 1990 - present. jtrumbo@ospr.dfg.ca.goventer text here


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

can spread rather rapidly, particularly in shallow water areas and areas with high nutrient enrichment. However, slower to spread than its frequent cohort parrotfeather, Myriophyllum aquaticum.


Sources of information:

personal observation, Joel Trumbo Butte County 1990 - present. jtrumbo@ospr.dfg.ca.goventer text here


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

Probably slilghtly increasing in the state.


Sources of information:

Observational, Trumbo and DiTomaso (ditomaso@vegmail.ucdavis.edu)


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

Aquatic and Riparian Weeds of the West. Joe DiTomaso and Evelyn Healy. University of California Agriculture and Natural Resources. Oakland, California. 2003.


Sources of information:

flowing water in canals and streams, transport on boats and boat trailers


Question 2.5 Potential for human-caused dispersal? B Observational
Identify dispersal mechanisms:

flowing water in canals and streams, transport on boats and boat trailers


Sources of information:

personal knowledge and observation, Joel Trumbo


Question 2.6 Potential for natural long-distance dispersal? A Observational
Identify dispersal mechanisms:

flowing water, on the bodies of migating waterfowl


Sources of information:

Aquatic and Riparian Weeds of the West. Joe DiTomaso and Evelyn Healy. University of California Agriculture and Natural Resources. Oakland, California. 2003.


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

has invaded numerous other global locations including Europe and Australia.


Sources of information:

Aquatic and Riparian Weeds of the West. Joe DiTomaso and Evelyn Healy. University of California Agriculture and Natural Resources. Oakland, California. 2003. The Jepson Manual, University of California Press, Berkeley and Los Angeles California. 1993.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? C Observational

My very rough estimate would be >5% but < 20% of freshwater aquatic sites have been invaded. frequency estimate


Sources of information:

personal observation, Joel Trumbo


Question 3.2 Distribution/Peak frequency? B Observational
Describe distribution:

one of the most common freshwater, emersed aquatic weeds in the State, but it is limited to freshwater sites.


Sources of information:

observation, Joel Trumbo, and Joe DiTomaso (ditomaso@vegmail.ucdavis.edu)


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 Unknown
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 Yes
Resprouts readily when cut, grazed, or burned Yes
Total points: 7
Total unknowns: 2
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, reservoirsC, 5% - 20%
Aquatic Systemsrivers, streams, canalsB, 20% - 50%
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 forest
riparian woodland
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): B

Infested Jepson Regions

Click here for a map of Jepson regions

  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest
  • Modoc Plateau
  • Mojave Desert