Plant Assessment Form

Torilis arvensis

Common Names: hedgeparsley; spreading hedgeparsley

Evaluated on: 11/28/05

List committee review date: 10/01/2006

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/Coop. Ext. Specialist
University of California, Davis
Weed Science Program, Robbins Hall
530-754-8715
ditomaso@vegmail.ucdavis.edu

List commitee members

Joe DiTomaso
John Randall
Peter Warner
Jake Sigg

General Comments

There is almost no published (or even unpublished) research available on this species.

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 2.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U
Impact?
Four-part score UCBD Total Score
B
1.2 ?Impact on plant community C. Minor Observational
1.3 ?Impact on higher trophic levels B. Moderate Anecdotal
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
13 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)
C. Low Other Published Material
2.5 ?Potential for human-caused dispersal B. Moderate 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)
A. Widespread Other Published Material
Distribution?
Total Score A
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? U
Identify ecosystem processes impacted:

No information available


Sources of information:

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

Can be a problem species for livestock and wildlife grazers and an nuisance to humans, but may not get to densities high enough to cause significant ecological impacts.


Sources of information:

DiTomaso, observational.


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

Fruit can cause problems in wildlife and livestock by sticking to fur and other body parts.


Sources of information:

Anecdotal information from local ranchers.


Question 1.4 Impact on genetic integrity? D Other Published Material

None. The only Torilis in California are T. arvensis and T. nodosa, both introduced.


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?
B Observational
Describe role of disturbance:

Inhabitats disturbed places (1). Common on roadsides and disturbed sites in Oregon (2).


Sources of information:

1. Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA
2. Roche, C. 1992. Hedgeparsley (Torilis arvensis (Hudson) Link). Pacific Northwest Extension Publication #418., Washington State University, University of Idaho, and Oregon State University Cooperative Extension.


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

Torilis arvensis is a fast spreading weed that seems for the most part to be under the radar screen. It has been in the Bay Area for more 30 years and it seems that in the last five to 10 years it has taken off.


Sources of information:

Bob Case, California Native Plant Society, Cal-IPC, and Contra Costa Ag. Commissioner's office (retired). E-mail 11/27/05.


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

Spreading.


Sources of information:

Bob Case, California Native Plant Society, Cal-IPC, and Contra Costa Ag. Commissioner's office (retired). E-mail 11/27/05.


Question 2.4 Innate reproductive potential? C Other Published Material
Describe key reproductive characteristics:

Annual. Reproduces by seed. Each flower produces two spiny burs, each with one seed. Most seeds germinate after the first fall rains in areas with mild winters and in spring where winters are more severe.


Sources of information:

Roche, C. 1992. Hedgeparsley (Torilis arvensis (Hudson) Link). Pacific Northwest Extension Publication #418., Washington State University, University of Idaho, and Oregon State University Cooperative Extension.
DiTomaso and Healy. 2006. Weeds of California. DANR, In press.


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

Burs can stick to clothing, equipment, pets, and livestock. Seeds can be spread as contaminents in hay, crop seed, or bedding material.


Sources of information:

Roche, C. 1992. Hedgeparsley (Torilis arvensis (Hudson) Link). Pacific Northwest Extension Publication #418., Washington State University, University of Idaho, and Oregon State University Cooperative Extension.


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

Spiny burs can stick to fur of wildlife. Fruits fall near the parent plant or disperse to greater distances with water, mud, and by clinging to the fur, feathers, and feet of animals, to the shoes and clothing of humans, and to vehicle tires.


Sources of information:

Roche, C. 1992. Hedgeparsley (Torilis arvensis (Hudson) Link). Pacific Northwest Extension Publication #418., Washington State University, University of Idaho, and Oregon State University Cooperative Extension.
DiTomaso and Healy. 2006. Weeds of California. DANR, In press.


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

Native to southern Europe and Eurasia. Present in the central, southern, mid-Atlantic and west coast states. Noxious weed of Washington.


Sources of information:

USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.


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

Throughout California, except Great Basin and deserts, to 1600 m. Habitat includes disturbed sites such as roadsides, urban areas, railroad rights-of-way and woodlands. Very common in foothill oak woodlands and grasslands on both east and west site of Central Valley.


Sources of information:

USDA, NRCS. 2005. The PLANTS Database, Version 3.5 (http://plants.usda.gov). Data compiled from various sources by Mark W. Skinner. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.


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

Most common in oak woodlands.


Sources of information:

DiTomaso, observational.


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 No
Seeds remain viable in soil for three or more years No
Viable seed produced with both self-pollination and cross-pollination Unknown
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: 2
Total unknowns: 1
Total score: C?

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 grasslandC, 5% - 20%
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 woodlandB, 20% - 50%
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
  • Sonoran Desert
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest