Plant Assessment Form

Lobularia maritima

Synonyms: Alyssum maritimum, A. odoratum, Clypeola maritima, Koniga m.

Common Names: sweet alyssum; sweet alison; seaside alyssum; seaside lobularia

Evaluated on: 1/20/06

List committee review date: 24/01/2006

Re-evaluation date:

Evaluator(s)

Peter J. Warner
California Department of Parks and Recreation; CNPS; Cal-IPC
P. O. Box 603, Little River, CA 95456
(707) 937-9176 (w); (707) 937-2278 (h)
pwarn@parks.ca.gov

List commitee members

Peter Warner
Jake Sigg
Joe DiTomaso
Cynthia Roye

General Comments

Not much quantified ecological information on this species is available. Assessment based primarily on limited internet search and personal observations by evaluator and others (see CalFlora reference).

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 D Observational
Impact?
Four-part score DCUD Total Score
C
1.2 ?Impact on plant community C. Minor Observational
1.3 ?Impact on higher trophic levels U. Unknown
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
15 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 Other Published Material
2.5 ?Potential for human-caused dispersal A. High Other Published Material
2.6 ? Potential for natural long-distance dispersal C. Rare Observational
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? D Observational
Identify ecosystem processes impacted:

Adds organic matter (litter) and undetermined amount of nutrients that could be substantial in some otherwise nutrient-poor substrates (e.g., rocky coastal bluffs) contributing to soil development or enrichment (1). However, this hypothesis has not been empirically validated. Weak inference, based on observations of this species and its litter in rock crevices on coastal bluffs (1); this is essentially an untested hypothesis, so does not merit a higher score.


Sources of information:

1. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

In some habitats, such as coastal terrace prairie and coastal scrub, this plant displaces native plants (especially annuals), in others, may occupy habitats not otherwise populated with native plants (1). Conservatively, has relatively minor impact on displacement of native plants, but this could be an underestimation of its impacts, especially on smaller native species (1).


Sources of information:

Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

No published or observational information.


Sources of information:

Question 1.4 Impact on genetic integrity? D Other Published Material

None likely(1); no congeneric species are native to California (2, 3). Inferred from lack of congeners native to California (1).


Sources of information:

1. Warner, PJ. 2006. Inference from published information. 707/937-2278; corylus@earthlink.net
2. CalFlora: Information on California plants for education, research and conservation. [web application]. 2000. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. [Accessed: 20 January 2006.
3. Hickman, JC (editor). 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley.


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

Disturbance clearly facilitates establishment of this species (1, 2, 3) yet is not essential if seed sources are locally abundant, especially in available ecological niches. Invasiveness appears to be of greater potential in early successional or disturbed sites (4), including dunes, creekbeds, rocky bluffs. Based on comments about habitat types, and physical characteristics of invaded sites (1, 2, 3), and observations of habitats and ecological niches occupied (4).


Sources of information:

1. Hickman, JC (editor). 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley.
2. CalFlora: Information on California plants for education, research and conservation. [web application]. 2000. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. [Accessed: 20 January 2006.
3. http://plants.montara.com. 2006.
4. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

Observations from landscaped environments, as well as coastal scrub, dune, and coastal bluff habitats, suggest this plant is capable of spreading rapidly into suitable, available niches in the garden or in the wild (1). In one garden I maintained (Sonoma Co.), a single alyssum plant planted one year often resulted in dozens of alyssum plants occupying several times more space by the following spring (1). Seeds are also clearly well-dispersed by wind along the coast, and plants flower and produce seeds much of the year (1).


Sources of information:

1. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

Probably increasing. Inference (3): Most observations have been posted within past 10 years (1), yet Jepson cites only waste sites as "habitat" (2). The sites I've observed supporting this plant, but yet have not been documented (3), suggest that occurrences of this species may be underreported.


Sources of information:

1. CalFlora: Information on California plants for education, research and conservation. [web application]. 2000. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. [Accessed: 20 January 2006.
2. Hickman, JC (editor). 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley.
3. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

Prolific and dense flowering over extended periods in milder climates (1); seeds do not appear persistent in garden soils (1); produces embryonic roots along cotyledon margins (2); resprouts well in the garden following shearing, at least for a few years (1).


Sources of information:

1. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net
2. Hickman, JC (editor). 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley.


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

Widely sold by too many businesses and web-merchandisers to list (e.g., see (1, 2); extremely common in window boxes, sidewalk planters, gardens, parking lots, flower pots (3). sheer volume of this species I've observed being sold and planted (3)


Sources of information:

1. http://davesgarden.com/pf/go/230/
2. http://www.maltawildplants.com/CRUC/Lobularia_maritima.html
3. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


Question 2.6 Potential for natural long-distance dispersal? C Observational
Identify dispersal mechanisms:

Not known for sure, but probably not great: fruits and seeds are relatively unsubstantial, although could be a food source for birds or rodents. Seeds probably do move in wind locally, given the observed spread of the species from adjacent gardens and other sources (1) into nearby wild landscapes. Inference (1) from observations.


Sources of information:

1. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

Numerous islands in Pacific (1) including Hawai'i; Australia (2); Washington (state; 3); Wyoming (4); California coastal counties, a few interior counties (5, 6). Maritime influence appears a common denominator for most out-of-state occurrences, with the notable exception of Wyoming. Not much specific information on the types of habitats invaded in other states or countries; general distribution suggests Lobularia is weedy mostly in milder coastal areas, with the notable exception of Wyoming. It's possible that new habitat types could be invaded, but most likely would appear to be coastal types already invaded.


Sources of information:

1. Pacific Island Ecosystems at Risk. 2006. http://www.hear.org/pier/species/lobularia_maritima.htm
2. http://tncweeds.ucdavis.edu/global/australia/ath.html
3. http://admin.urel.washington.edu
4. http://www.uwyo.edu/
5. CalFlora: Information on California plants for education, research and conservation. [web application]. 2000. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. [Accessed: 20 January 2006.
6. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

Coastal bluffs and dunes, coastal scrub, coastal terrace prairie, coastal salt marshes, riparian corridors, dry interior S. Calif. washes, disturbed urban and waste sites (1, 2, 3, 4, 5, 6)


Sources of information:

1. CalFlora: Information on California plants for education, research and conservation. [web application]. 2000. Berkeley, California: The CalFlora Database [a non-profit organization]. Available: http://www.calflora.org/. [Accessed: 20 January 2006.
2. http://plants.montara.com
3. http://www.asla-sandiego.org
4. http://www.friendsofcortemaderacreek.org
5. Hickman, JC (editor). 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley.
6. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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

Close to unknown, but does not appear widely distributed except in scattered locations (1) No documentation, so a conservative estimate (1) of the species' distribution in the listed types invaded.


Sources of information:

1. Warner, PJ. 2006. Personal observations, 1995-2006. San Mateo, San Francisco, Marin, Sonoma, Mendocino Counties. 707/937-2278; corylus@earthlink.net


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 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 Yes
Resprouts readily when cut, grazed, or burned Yes
Total points: 8
Total unknowns: 1
Total score: A?

Related traits:

Prolific and dense flowering over extended periods in milder climates (1); seeds do not appear persistent in garden soils (1); produces embryonic roots along cotyledon margins (2); resprouts well in the garden following shearing, at least for a few years (1).

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 scrubD, < 5%
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 grassland
Great Basin grassland
vernal pool
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swampD, < 5%
Riparian and Bottomland habitatriparian forest
riparian woodlandD, < 5%
riparian scrub (incl.desert washes)D, < 5%
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): A
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions

  • Cascade Range
  • Central West
  • Great Valley
  • Northwest
  • Sierra Nevada
  • Southwest
  • Desert Province
  • Mojave Desert
  • Sonoran Desert