Plant Assessment Form

Trifolium hirtum

Common Names: rose clover

Evaluated on: 2/22/05

List committee review date: 08/07/2005

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 DiTomaso
University of California-Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee members

Joe DiTomaso
Joanna Clines
Cynthia Roye
Doug Johnson

General Comments

Common species of Great Basin and valley and foothill grasslands.

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 Other Published Material
Impact?
Four-part score CCDU Total Score
C
1.2 ?Impact on plant community C. Minor Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels D. Negligible Other Published Material
1.4 ?Impact on genetic integrity U. Unknown
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Reviewed Scientific Publication
Invasiveness?
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management C. Stable Other Published Material
2.3 ?Recent trend in total area infested within state C. Stable Other Published Material
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal A. High Other Published Material
2.6 ? Potential for natural long-distance dispersal D. None Other Published Material
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
B. Moderate Reviewed Scientific Publication
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? C Other Published Material
Identify ecosystem processes impacted:

Nitrogen fixing (1). Stabilizes soil and exhausts all available soil moisture (2). Co-exists with other native legumes for nitrogen fixation is an important component of the community.


Sources of information:

1. DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States
2. Love, R. M. (1985). Rose Clover Trifolium-Hirtum. Taylor, N. L. (Ed.). Agronomy: A Series of Monographs, No. 25. Clover Science and Technology. Xx+616p. American Society of Agronomy, Inc., Crop Science Society of America, Inc., Soil Science Society of America, Inc., Publishers: Madison, Wis., USA. Illus. 1985. 535-546.


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

Prevents establishment of other plants because it uses soil moisture (1). Generally in areas with abundant rose clover there is still relatively high diversity.


Sources of information:

1. Love 1985.


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

Eaten by cattle, sheep, deer. Quail and robins eat seeds. Does not cause estrogenic effects (sterility) in sheep (1).


Sources of information:

1. Love 1985.


Question 1.4 Impact on genetic integrity? U

There are at least 30 native species of Trifolium in California. No information on hybridization.


Sources of information:

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


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

Inhabits disturbed places (1). Invaded up to 95 m into oak woodland, 35m into serpentine meadows, and 5m into serpentine seeps from revegetated mine areas (2), but does not form dense infestations in these areas.


Sources of information:

1. DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States
2. Williamson, J. and S. Harrison (2002). "Biotic and abiotic limits to the spread of exotic revegetation species." Ecological Applications 12(1): 40-51.


Question 2.2 Local rate of spread with no management? C Other Published Material
Describe rate of spread:

Does not tend to become a very concentrated dense patch. Generally becomes part of the community.


Sources of information:

DiTomaso, observational


Question 2.3 Recent trend in total area infested within state? C Other Published Material
Describe trend:

Has been present for so long it is probably already in all the places that it could be introduced.


Sources of information:

DiTomaso, observational


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

Annual. Flowers April to May. Reproduces by seed. Fruits fall near the parent plant but disperse longer distances. Some seeds are hard-coated and require scarification or decomposition of the seed coat to germinate (1). Seeds remain viable for many years (2). Colonizes well due to rapid morphological changes and by retention of some outbreeding and genetic variation in some populations (3).


Sources of information:

1. DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States
2. Love 1985
3. Jain, S. K. and P. S. Martins (1979). Ecological Genetics of the Colonizing Ability of Rose Clover Trifolium-Hirtum. American Journal of Botany 66(4): 361-366.


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

Used as rangeland forage. Can be dispersed by turf maintenance, agricultural acitivities, as seed contaminants, and by clinging to shoes, clothing, or tires. Grazing favors survival (1). Counts of seeds in droppings of cattle grazing on rose clover during the summer showed an average of 6500 undigested seeds/dropping, 85% of which were still viable (2).


Sources of information:

1. DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States.
2. Love 1985


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

Can cling to fur and feet of animals, but this is an uncommon method of moving seed >1 km..


Sources of information:

DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States.


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

Native to Mediterranean and Asia (1). Also invades Oregon and the southeastern U.S. (2) Scoring as C because already widespread in California.


Sources of information:

1. Love 1985.
2. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? B Reviewed Scientific Publication

Planted in California starting in the 1940's (1). Present throughout California, except deserts and the Great Basin, to 2060m. Inhabits roadsides, fields, grassland, and open slopes (2). Hard seeds allow it to survive on drier range sites (3). Found in oak woodland and serpentine meadows (4).


Sources of information:

1. Love 1985.
2. DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States
3. Graves, W. L., B. L. Kay, et al. "Hardseeded Spanish subclover finds a place in southern California." Calif Agric Calif Agric Exp Stn 41(11/12): 8-10.
4. Williamson, J. and S. Harrison (2002). "Biotic and abiotic limits to the spread of exotic revegetation species." Ecological Applications 12(1): 40-51.


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

Common species of Great Basin and valley and foothill grasslands.


Sources of information:

DiTomaso, observational
Joanna Clines, US Forest Service, pers. obs.


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 No
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 No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned No
Total points: 7
Total unknowns: 0
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 grasslandB, 20% - 50%
Great Basin grasslandB, 20% - 50%
vernal pool
meadow and seepD, < 5%
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 woodlandB, 20% - 50%
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): B
Distribution (highest score): B

Infested Jepson Regions

Click here for a map of Jepson regions

  • CA Floristic Province
  • Cascade Range
  • Central West
  • Desert Province
  • Mojave Desert
  • Sonoran Desert
  • Great Valley
  • Modoc Plateau
  • Northwest
  • Sierra Nevada
  • Southwest