Plant Assessment Form

Raphanus sativus

Synonyms: R. raphanistrum var. sativus

Common Names: wild radish

Evaluated on: 1/21/05

List committee review date: 30/06/2005

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
Jake Sigg
Cynthia Roye
Peter Warner

General Comments

The two species of radish readily hybridize and show wide variation in morphology, so it is not possible to separate them for PAFs.

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 2.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U
Impact?
Four-part score UCDD Total Score
C
1.2 ?Impact on plant community C. Minor Observational
1.3 ?Impact on higher trophic levels D. Negligible Other Published Material
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
10 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 Other Published Material
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Other Published Material
2.5 ?Potential for human-caused dispersal B. Moderate Other Published Material
2.6 ? Potential for natural long-distance dispersal C. Rare 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 B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very 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? U
Identify ecosystem processes impacted:

no information


Sources of information:

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

Primarily found in agricultural areas or roadsides. Not often found in wildlands and when present does not form dense patches (1). Invasive in coastal dunes, prairie, and scrub in Marin, Sonoma, and Mendocino counties (2).


Sources of information:

1. Joe DiTomaso, Weed Science Program, UC Davis, observational.
2. Peter Warner, California State Parks, Mendocino, pers. obs.


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

Livestock that ingest large quantities of seeds can develop irritation of the digestive tract. Not in high enough density in wildlands to cause a problem.


Sources of information:

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


Question 1.4 Impact on genetic integrity? D Other Published Material

Both species of radish in California are introduced. They are well-known for their ability to hybridize. Populations in inland areas show mostly R. raphanistrum characters, while coastal populations are more similar to R. sativus (1).


Sources of information:

1. Klinger, T. and N. C. Ellstrand 1994. Engineered genes in wild populations: Fitness of weed-crop hybrids of Raphanus sativus. Ecological Applications 4(1): 117-120.


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

Mostly a weed of disturbed areas, but also in coastal rangelands and adjacent to (but not alongside) roads and trails (1). Present on roadsides, pastures, crop fields, orchards, vineyards, old gardens, playgrounds, parks, and other disturbed places (2).


Sources of information:

1. Peter Warner, ecologist, California State Parks, Mendocino, pers. observation
2. DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


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

Does not really form large patches


Sources of information:

DiTomaso, observational.


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

It already exists throughout California, so presumably it isn't spreading quickly at this time.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


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

Winter or summer annual, sometimes biennial. Elongate pods do not open to release seeds. Buried seeds of R. raphanistrum can survive 20-30 years. R. raphanistrum can produce large quantities of seeds under favorable conditions. Germination occurs in fall after the first significant rain, but some seeds continue to germinate through spring or at other times when conditions are favorable.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


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

Fruits and seeds can disperse with human activities, agricultural operations, and as contaminants of crop and hay.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


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

Seeds and fruits can be dispersed by water and animals.


Sources of information:

DiTomaso and Healy. 2006. Weeds of California. UC DANR Publ. #3488.


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

Native to the Mediterranean. Present in many U.S. states. Listed as noxious weed (secondary) in Minnesota and in Australia, but mainly because it impacts agriculture. Scoring as C because it is already widespread.


Sources of information:

DiTomaso and Healy in prep


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

Occurs throughout California, except deserts, Great Basin, and some mountain areas, to 1000m. Present on roadsides, pastures, crop fields, orchards, vineyards, old gardens, playgrounds, parks, and other disturbed places (1). One of the most invasive plants in coastal hind dunes and adjacent prairie and scrub in Marin, Sonoma, and Mendocino counties (2).


Sources of information:

1. DiTomaso and Healy 2006
2. Peter Warner, California State Parks, Mendocino, pers. obs.


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

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 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 No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned No
Total points: 4
Total unknowns: 1
Total score: B?

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
DunescoastalD, < 5%
desert
interior
Scrub and Chaparralcoastal bluff scrubD, < 5%
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 prairieD, < 5%
valley and foothill grasslandD, < 5%
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 woodlandD, < 5%
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): D

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