Plant Assessment Form

Ranunculus repens

Common Names: creeping buttercup

Evaluated on: 12/30/04

List committee review date: 11/02/2005

Re-evaluation date:


Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709

List committee members

Carla Bossard
John Randall
Cynthia Roye
Jake Sigg
Peter Warner

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 C. Minor Reviewed Scientific Publication
Four-part score CCCD Total Score
1.2 ?Impact on plant community C. Minor Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels C. Minor Reviewed Scientific Publication
1.4 ?Impact on genetic integrity D. None Reviewed Scientific Publication
2.1 ?Role of anthropogenic and natural disturbance in establishment C. Minor Observational
Total Points
9 Total Score C
2.2 ?Local rate of spread with no management C. Stable 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 Reviewed Scientific Publication
2.6 ? Potential for natural long-distance dispersal C. Rare Observational
2.7 ?Other regions invaded C. Already invaded Observational
3.1 ?Ecological amplitude/Range
(see Worksheet C)
B. Moderate Observational
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
C. Low 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? C Reviewed Scientific Publication
Identify ecosystem processes impacted:

May deplete potassium from soil, although the evidence for this sounds somewhat circumstantial (1).

Sources of information:

1. Lovett-Doust, J., L. Lovett-Doust, and A. T. Groth. 1990. The biology of Canadian weeds. 95. Ranunculus repens. Canadian Journal of Plant Science. 70:1123-1141.

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

May secrete toxins that cause neighboring plants to suffer N deficiency (1). Crowds out other plants (2).

Sources of information:

1. Lovett-Doust et al. 1990.
2. Burrill L.C., 1992. Creeping Buttercup. Ranunculus repens L. Pacific Northwest Publication #PNW 399.

Question 1.3 Impact on higher trophic levels? C Reviewed Scientific Publication
Identify type of impact or alteration:

Poisonous to livestock and humans (1, 2). No information on effects on native species. Scored as C because no info on how it affects native species

Sources of information:

1. Lovett-Doust et al. 1990
2. Fuller T.F., McClintock E. 1986. Poisonous Plants of California. University of California Press, Berkeley. pp. 221-222.

Question 1.4 Impact on genetic integrity? D Reviewed Scientific Publication

There are numerous native Ranunculus species, but experimental crosses using Ranunculus species are rarely successful. No close hybrids have been recorded for R. repens.

Sources of information:

1. Lovett-Doust et al. 1990

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

Pioneer colonizer of ploughed land or smaller disturbed sites. Common weed of lawns, pastures,and waste places (1).

Sources of information:

1. Lovett-Doust et al. 1990.
2. Sarukhan, J, and Harper, J. L. 1973. Studies on plant demography: Ranunculus repens L., Ranunculus bulbosus L. and Ranunculus acris L. i. population flux and survivorship. Journal of Ecology. 61: 675-716.

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

Does not spread much.

Sources of information:

Peter Warner, California State Parks, Personal Observation

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


Sources of information:

Peter Warner, California State Parks, Personal Observation

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

Perennial herb with stolons that readily root at nodes, even when there is no direct contact with soil. Insect-pollinated. A small degree of selfing may occur. Plants produce 1-5 flowers and most flowers produce 20 or fewer seeds (maximum number of seeds produced was 77). One quarter of plants that flower set seed (1). Seed bank is large (up to 11,400 seeds/m2) and persistent (1). Seeds can survive 16 years (2). Clones show large variation in their amount of sexual reproduction (3).

Sources of information:

1. Lovett-Doust et al. 1990
2. Lewis, J. 1973. Longevity of crop and weed seeds: Survival after 20 years in soil. Weed Research. 13: 179-191
3. Lynn, D.E., and S. Waldren. 2001. Variation in life history characteristics between clones of Ranunculus repens grown in experimental garden conditions. Weed Research. 41:421-432.

Question 2.5 Potential for human-caused dispersal? C Reviewed Scientific Publication
Identify dispersal mechanisms:

Dispersed in hay (1), in dung of farm animals, tire treads, and "in the trouser cuffs of boys who regularly walk through fields" (2).

Sources of information:

1. Burrill 1992
2. Lovett-Doust et al. 1990

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

Wind dispersal, produces winged achenes. Probably does not disperse more than 1km. Seeds ingested by birds.

Sources of information:

1. Lovett-Doust et al. 1990
2. Burrill 1992

Question 2.7 Other regions invaded? C Observational
Identify other regions:

Native to Europe. May have been introduced to North America with settlers. Present in broad band within U.S. and Canada between 38 and 50 degrees N. Also introduced to central and south America, New Zealand, and Australia (1). Occurs in Pacific northwest, mostly west of the Cascades (2).

Sources of information:

1. Lovett-Doust et al. 1990
2. Burrill 1992

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

We have no information from California, but in Canada it is common in pastures, grasslands, woodlands, swamps, and along the margins of ponds, rivers and ditches. In woodlands, it is restricted to clearings, forest margins, and paths where light is available. Can tolerate some salinity and is found on beaches, salt marshes, and on the margins of tidal estuaries. Usually found in heavy wet clay soils, can withstand waterlogging (1). In California, occurs in Marin, Sonoma, Mendocino, Napa, Monterey, Santa Barbara, Sacramento, and Nevada counties (2).

Sources of information:

1. Lovett-Doust et al. 1990
2. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 ( National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

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

Sources of information:

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Yes
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually Unknown
Seeds remain viable in soil for three or more years Yes
Viable seed produced with both self-pollination and cross-pollination Yes
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: 11
Total unknowns: 1
Total score: A?

Related traits:

I calculated >1000 seeds per square meter based on 5 flowers/plant, and 20 seeds/flower, assuming many small plants within a square meter. Not sure about last two questions, but resprouting seems likely based on the presence of stolons.

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
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
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 forestC, 5% - 20%
riparian woodlandC, 5% - 20%
riparian scrub (incl.desert washes)
Woodlandcismontane woodland
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forestC, 5% - 20%
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): B
Distribution (highest score): C

Infested Jepson Regions

Click here for a map of Jepson regions

  • Cascade Range
  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest
  • Modoc Plateau