Plant Assessment Form

Cakile maritima

Common Names: European sea rocket

Evaluated on: 5/20/04

List committee review date: 23/11/2017

Re-evaluation date:

Evaluator(s)

John J. Knapp/ Invasive Plant Program Manager
Catalina Island Conservancy
P.O. 2739 Avalon, CA 90704
(310) 510-1299
jknapp@catalinaconservancy.org
Joseph M. DiTomaso
University of California, Davis
Dept. Plant Sci., Mail Stop 4, Davis, CA 95616
530-754-8715
jmditomaso@ucdavis.edu

List commitee 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? 3.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes C Reviewed Scientific Publication
Impact?
Four-part score CCCD Total Score
C
1.2 ?Impact on plant community C. Minor Other Published Material
1.3 ?Impact on higher trophic levels C. Minor 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
12 Total Score B
2.2 ?Local rate of spread with no management B. Increases less rapidly Reviewed Scientific Publication
2.3 ?Recent trend in total area infested within state C. Stable Reviewed Scientific Publication
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal C. Low Reviewed Scientific Publication
2.6 ? Potential for natural long-distance dispersal A. Frequent Reviewed Scientific Publication
2.7 ?Other regions invaded C. Already invaded Reviewed Scientific Publication
3.1 ?Ecological amplitude/Range
(see Worksheet C)
D. Narrow Reviewed Scientific Publication
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
A. High Other Published Material

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:

C. maritima demonstrates weak allelophy. C. maritima has demonstrated evidence of allelopathic effects in replicated growth chamber experiments; however, the effect was not detected under field experiments.


Sources of information:

Boyd, R.S. 1993. Replacement of Cakile endentula by C. maritima in the strand habitat of California. American Midland Naturalist, 130(2):209-228.


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

C. maritima has lead to the reduction, and in some situations the extirpation of Abronia spp. However, in most places its impacts are minor. C. maritima is invasive, with the ability to produce more seed, tolerate disturbance, and disperse greater distances than native Abronia spp.


Sources of information:

Wood, L. 19??. Dune stabilization. Fremontia, ?(?):27.
Pers. Obs. Joe DiTomaso, Carla Bossard, Jake Sigg, Peter Warner 9/15/05


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

Competes for pollination visitation with native vegetation but this may not impact native species. Although self-compatible, insect pollination plays an intergral part in reproduction.


Sources of information:

Barbour, M.G. and Rodman, J.E. 1970. Saga of the west coast sea-rockets: Cakile edentula ssp. californica and C. maritima. Rhodora, 72(791):370-386.


Question 1.4 Impact on genetic integrity? D Other Published Material

No hybridization is known to occur with native California taxa. No related native California taxa in the genus Cakile.


Sources of information:

Hickman, J.C. (ed.). 1993. The Jepson manual of higher plants of California. Pp. 406. University of California Press, Berkeley.


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
B Reviewed Scientific Publication
Describe role of disturbance:

Establishes quickly on beaches and dunes that are frequently disturbed and have low diversity. Able to colonize beach and dune habitats along coast that are frequently disturbed by surf and wind, and have low biodiversity.


Sources of information:

Haubensak, K. 1999. Cakile maritima. Channel Islands National Park Sevice Species Literature Review. Unpublished.


Question 2.2 Local rate of spread with no management? B Reviewed Scientific Publication
Describe rate of spread:

No populations were recorded in the first Catalina Island flora in 1923, but by 1966, C. maritima was widespread throughout the beaches and dunes of the Island, and has a similar distribution and abundance in 2003. If C. maritima can survive into a second or even a third year of reproduction, it can produce an 18-fold difference in seed output. Seed production is increased during colonization, and has a high fecundity.


Sources of information:

Thorne, R.F. 1967. A Flora of Santa Catalina Island, California. Aliso, 6(3):1-77.
Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.
Barbour, M.G. and Rodman, J.E. 1970. Saga of the west coast sea-rockets: Cakile edentula ssp. californica and C. maritima. Rhodora, 72(791):370-386.
Boyd, R.S. 1988. Hebivory and species replacement in the west coast searockets (Cakile, Brassicaceae). American Midland Naturalist, 119(2):304-317.
Boyd, R.S. 1993. Replacement of Cakile endentula by C. maritima in the strand habitat of California. American Midland Naturalist, 130(2):209-228.
Barbour, M.G. 1970. Seedling ecology of Calike maritima along the California coast. Bulletin of the Torrey Botatnical Club, 97(5):280-289.


Question 2.3 Recent trend in total area infested within state? C Reviewed Scientific Publication
Describe trend:

Occupies all avaliable habitats along the California and Baja coast. Santa Cruz Island. On Catalina Island, 101,225 square feet are infested. C. maritima has similar xeric region of origin similar to California, with the average temperature at Santa Cruz Island being the optimal for germination.


Sources of information:

Wood, L. 19XX. Dune stabilization. Fremontia, X(X):27.
Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.
Boyd, R.S. 1988. Hebivory and species replacement in the west coast searockets (Cakile, Brassicaceae). American Midland naturalist, 119(2):304-317.
Barbour, M.G. 1970. Seedling ecology of Calike maritima along the California coast. Bulletin of the Torrey Botatnical Club, 97(5):280-289.


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

Seed bank persists for al least 2 years in foredunes. C. maritima can survive disturbance into a second or even a third year of reproduction, producing an 18-fold difference in seed output. Seed production is increased during colonization, and has a high fecundity. Self pollination is possible. 90% seed set. Classified as an annual species; however, has shown to be biennial. Seeds are readily buried in foredunes, allowing them to escape predation by deer mice (Peromyscus maniculatus), which can remove 95% of seed, causing only 20% seed survivorship. During colonization of disturbed sites of native Abronia maritima, C. maritima will allocate energy to seed production rather than to biomass to survive until the next year leading to a greater level of invasiveness. C. maritima is a faculative annual, germinating in the winter and fruiting in the summer. One seed per fruit segment.


Sources of information:

Haubensak, K. 1999. Cakile maritima. Channel Islands National Park Sevice Species Literature Review. Unpublished.
Wood, L. 19XX. Dune stabilization. Fremontia, X(X):27.
Barbour, M.G. and Rodman, J.E. 1970. Saga of the west coast sea-rockets: Cakile edentula ssp. californica and C. maritima. Rhodora, 72(791):370-386.
Boyd, R.S. 1988. Hebivory and species replacement in the west coast searockets (Cakile, Brassicaceae). American Midland Naturalist, 119(2):304-317.
Boyd, R.S. 1993. Replacement of Cakile endentula by C. maritima in the strand habitat of California. American Midland Naturalist, 130(2):209-228.
Barbour, M.G. 1970. Seedling ecology of Calike maritima along the California coast. Bulletin of the Torrey Botatnical Club, 97(5):280-289.
Brown, K. and Brooks, K. 2002. Bushland weeds: a practical guide to their management with case studies from Swan Coastal Plain and beyond. Environmental Weeds Action Network. Greenwood, Australia.


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

Sand transport, ship ballast, and trampling account for human-caused dispersal. The relocation of sand from areas infested with C. maritima to new locales, and trampling by hikers and campers in dunes may allow for plant material to roll (tumble weed effect), thus dispersing seed.


Sources of information:

Rodman, J.E. 1986. Introduction, establishment and replacement of sea-rockets (Cakile, Cruciferae) in Australia. Journal of Biogeography, 13(2):159-171.
Wood, L. 19XX. Dune stabilization. Fremontia, X(X):27.
Knapp J.J. 2004. Personal observations from 2000-2004 of people walking through infestations on beaches of California and Catalina Island. (310) 510-2821, jknapp@catalinaconservancy.org.


Question 2.6 Potential for natural long-distance dispersal? A Reviewed Scientific Publication
Identify dispersal mechanisms:

Fruits are adapted for both short and long distance dispersal by wind and water respectively. In California, C. maritima dispersed at a rate of 53 km per year. Deer mice act as microdispersal vectors; however, their herbivory has also impacted C. maritima. Fruits are composed of two segments and have superb dispersability- the upper segment detaches and is carried by the sea, allowing for 50% of detached fruits to stay afloat for over 100 days. The lower segment remains attached to the plant until wind events cause the plant to roll along the surface, thus breaking off the fruits break. Deer mice cachet seeds.


Sources of information:

Haubensak, K. 1999. Cakile maritima. Channel Islands National Park Sevice Species Literature Review. Unpublished.
Rodman, J.E. 1986. Introduction, establishment and replacement of sea-rockets (Cakile, Cruciferae) in Australia. Journal of Biogeography, 13(2):159-171.
Boyd, R.S. 1988. Microdistribution of the beach plant Cakile maritima (Brassicaceae) as influenced by a rodent herbivore. American Journal of Botany, 75(10):1540-1548.
Boyd, R.S. 1993. Replacement of Cakile endentula by C. maritima in the strand habitat of California. American Midland Naturalist, 130(2):209-228.


Question 2.7 Other regions invaded? C Reviewed Scientific Publication
Identify other regions:

Eastern North America, western and southern Australia, Tasmania, and New Zealand are invaded.


Sources of information:

Haubensak, K. 1999. Cakile maritima. Channel Islands National Park Sevice Species Literature Review. Unpublished.
Rodman, J.E. 1986. Introduction, establishment and replacement of sea-rockets (Cakile, Cruciferae) in Australia. Journal of Biogeography, 13(2):159-171.
Barbour, M.G. 1970. Seedling ecology of Calike maritima along the California coast. Bulletin of the Torrey Botatnical Club, 97(5):280-289.


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

Introduced to California, north of San Francisco in the 1930's. In 1967, Thorne found C. maritima to be well-established, while other botanists found it abundant on Santa Cruz, San Clemente and San Nicolas islands. First recorded on Catalina Island 1966 as well-established on beaches around the Island. Coastal beaches, dunes and sandy stream mouths. Occupies coast line with sandy substrate. On Catalina Island in 2003, 21 populations were recorded and the following are the percentages of habitat infested: beach and dune- 1.4%, and riparian creek mouth-<0.00%.


Sources of information:

Barbour, M.G. 1970. Seedling ecology of Calike maritima along the California coast. Bulletin of the Torrey Botatnical Club, 97(5):280-289.
Barbour, M.G. and Rodman, J.E. 1970. Saga of the west coast sea-rockets: Cakile edentula ssp. californica and C. maritima. Rhodora, 72(791):370-386.
Thorne, R.F. 1967. A flora of Santa Catalina Island, California. Aliso, 6(3):1-77.
Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.
Haubensak, K. 1999. Cakile maritima. Channel Islands National Park Sevice Species Literature Review. Unpublished.


Question 3.2 Distribution/Peak frequency? A Other Published Material
Describe distribution:

Very common, but not typically in dense patches.


Sources of information:

Barbour, M.G. 1970. Seedling ecology of Calike maritima along the California coast. Bulletin of the Torrey Botatnical Club, 97(5):280-289.
Barbour, M.G. and Rodman, J.E. 1970. Saga of the west coast sea-rockets: Cakile edentula ssp. californica and C. maritima. Rhodora, 72(791):370-386.
Thorne, R.F. 1967. A flora of Santa Catalina Island, California. Aliso, 6(3):1-77.
Knapp, J.J. 2004. Catalina Invasive Plant Ranking Plan for the Catalina Island Conservancy. Unpublished.
Haubensak, K. 1999. Cakile maritima. Channel Islands National Park Sevice Species Literature Review. Unpublished.
Rodman, J.E. 1986. Introduction, establishment and replacement of sea-rockets (Cakile, Cruciferae) in Australia. Journal of Biogeography, 13(2):159-171.


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 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 No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned No
Total points: 5
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
DunescoastalA, > 50%
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 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): D
Distribution (highest score): A

Infested Jepson Regions

Click here for a map of Jepson regions

  • Central West
  • Sonoran Desert
  • Northwest
  • Southwest