Plant Assessment Form

Euphorbia terracina

Common Names: carnation spurge; Geraldton carnationweed

Evaluated on: 6/30/05

List committee review date: 08/07/2005

Re-evaluation date:


Joseph M. DiTomaso
University of California, Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616

List committee members

Jake Sigg
Peter Warner
Bob Case
John Knapp
Elizabeth Brusati

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 2 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U. Unknown Reviewed Scientific Publication
Four-part score UBUU Total Score
1.2 ?Impact on plant community B. Moderate Other Published Material
1.3 ?Impact on higher trophic levels U. Unknown
1.4 ?Impact on genetic integrity U. Unknown
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
Total Points
11 Total Score B
2.2 ?Local rate of spread with no management A. Increases 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 Observational
2.5 ?Potential for human-caused dispersal D. Does not occur Observational
2.6 ? Potential for natural long-distance dispersal C. Rare Other Published Material
2.7 ?Other regions invaded U. Unknown Anecdotal
3.1 ?Ecological amplitude/Range
(see Worksheet C)
C. Limited Other Published Material
Total Score C
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 Reviewed Scientific Publication
Identify ecosystem processes impacted:

No information available. Considered a noxious weed, but is primarily restricted to the south coast region of the state.

Sources of information:

Question 1.2 Impact on plant community composition,
structure, and interactions?
B Other Published Material
Identify type of impact or alteration:

Similar to leafy spurge (1). Allelopathic, dense roots outcompete other plants, reduces germination of native plants (based on leafy spurge references). Does not currently form the dense stands typical of leafy spurge. It often forms dense patches and generally flowers March through August.

Sources of information:

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

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

Like many other spurges, geraldton carnationweed is reported to have toxic sap, but there are no records of problems in California.

Sources of information:

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

Question 1.4 Impact on genetic integrity? U

There are seven native Euphorbia in California, so potential for hybridization is there. There is no evidence for hybridization though.

Sources of information:

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

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

Euphorbia spp. often found in waste places, roadsides, fields, pastures, but can move into relatively undisturbed sites. It has moved into the coast scrub areas of southern California that do not appear to be disturbed.

Sources of information:

Jo Kitz and Joe DiTomaso, observational

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

Appears to be spreading locally, but not at rates observed for leafy spurge.

Sources of information:

Jo Kitz, observational.

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

Expanding range along southern California coast.

Sources of information:

Observational, Jo Kitz

Question 2.4 Innate reproductive potential? A Observational
Describe key reproductive characteristics:

Perennial. Monoecious. Spreads by seed or division. Crown buds develop at the bases of stems and can produce new shoots or roots. Probably has long lived seeds as do most other Euphorbia species.

Sources of information:

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

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

Not typically sold in the nursery industry so opportunities for human dispersal are rare. Not found for sale in an internet search.

Sources of information:

DiTomaso, observational.
E. Brusati, Cal-IPC, observational

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

Seed primarily fall to ground below parent plant. No mechanism of long distance dispersal. Can occur close to water and this could move seed long distances on occasion.

Sources of information:

DiTomaso, observational.

Question 2.7 Other regions invaded? U Anecdotal
Identify other regions:

It also occurs in Pennsylvania. No record of the types of communities in other regions.

Sources of information:

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

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

Geraldton carnationweed inhabits disturbed places, grassland, coastal bluffs (particularly near Malibu), dunes, salt marsh, riparian areas, and oak woodlands in the South Coast (Los Angeles Co.).

Sources of information:

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

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

Uncommon in California, but expanding range.

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 Yes
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 No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 6
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, reservoirs
Aquatic Systemsrivers, streams, canals
Scrub and Chaparralcoastal bluff scrubD, < 5%
coastal scrubD, < 5%
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 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): D

Infested Jepson Regions

Click here for a map of Jepson regions

  • Central West
  • Sierra Nevada
  • Southwest