Source: California Invasive Plant Council


URL of this page: http://www.cal-ipc.org/site/paf/545
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Cal-IPC Plant Assessment Form

For use with "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands"
by the California Invasive Plant Council and the Southwest Vegetation Management Association

Table 1. Species and Evaluator Information

Species name
(Latin binomial):
The official Latin binomial name for this species. Specify only one name here. Additional species names may go into the Synonyms field.

Limonium duriusculum

Synonyms:
Additional Latin binomial names for this species. Separate multiple names with a ; character. Please avoid narrative descriptions, and list only the binomial names.
Statice companyonis; Limonium thiniense; Limonium duriusculum subsp. companyonis; Limonium duriusculum subsp. thiniense
Common names:
Common names for this species. Separate multiple names with a ; character.
European sea lavendar
Evaluation date:
The date(s) when this species PAF was filled out, modified, or reviewed. This is free-form text, so it may include multiple dates or other notes.
January 8, 2017
Evaluator #1 Mona Robison/Science Program Manager
Cal-IPC
510-843-3902 ext 205
rrobison@cal-ipc.org
List committee members: Elizabeth Brusati, Tim Hyland, Eric Wrubel, Irina Irvine, Holly Forbes, Jutta Burger, Naomi Fraga, Denise Knapp, Chris McDonald, Ron Vanderhoff, John Knapp
Committee review date: January 26, 2017
List date: June 2, 2017
Re-evaluation date(s):
General comments
on this assessment:
Enter any additional notes about this assessment, such as factors affecting the reliability or completeness of the answers, likely affects of impacts, or research which is not specific to California but is still relevant in the evaluation of this species.
L. ramosissimum and L. duriusculum are quite frequently mis-identified in the field and there may have been a common propensity for many biologists to record any small, clumping, invasive Limonium as L. ramosissimum. As such, I suspect that L. duriusculum may be significantly under-reported, at least in the south coast region. Vanderhoff, pers. comm. In one important reference on L. duriusculum in Carpenteria Marsh (Hubbard and Page 1997) the species was originally referred to as L. ramosissimum and later re-identified as L. duriusculum (Kelch, pers. comm.), so confusion was introduced in the literature when using that reference.

Table 2. Criteria, Section, and Overall Scores

Overall Score

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistribution
AA BAnyHighNo Alert
AC DAnyModerateAlert
BA BA BModerateNo Alert
BA BC DModerateAlert
BC DAnyLimitedNo Alert
CAA BModerateNo Alert
CAC DLimitedNo Alert
CBAModerateNo Alert
CBB DLimitedNo Alert
CCAnyLimitedNo Alert
DAnyAnyNot ListedNo Alert

Moderate

Alert Status

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistributionAlert
AA or BC or DAlert
BA or BC or DAlert

No Alert

Documentation

The total documentation score is the average
of Documentation scores given in Table 2.

Reviewed Scientific Publication4 points
Other Published Material3 points
Observational2 points
Anecdotal1 points
Unknown or No Information0 points

3.5 out of 5

Score Documentation
1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
B. Moderate Other Published Material
Impact
Section 1 Scoring Matrix
Q 1.1Q 1.2Q 1.3Q 1.4Score
AAAnyAnyA
ABA,BAnyA
ABC,D,UAnyB
AC,D,UAnyAnyB
BAAAnyA
BABAA
BAB,CB-D,UB
BAC,D,UAA
BAC,D,UB-D,UB
BBAAA
BC,D,UAAB
BB-DAB-D,UB
BB-DB-D,UAnyB
BD,UC,D,UA-BB
BD,UC,D,UC,D,UC
C-D,UAAAnyA
CBAAnyB
CA,BB-D,UAnyB
CC,D,UAnyAnyC
DA,BBAnyB
DA,BC,D,UAnyC
DCAnyAnyC
DD,UAnyAnyD
UAB,CAnyB
UB,CA,BAnyB
UB,CC,D,UAnyC
UUAnyAnyU


Four-part score
BABC

Total Score
B
1.2 Impact on plant community
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
A. Severe Reviewed Scientific Publication
1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
B. Moderate Reviewed Scientific Publication
1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
C. Minor / Low Reviewed Scientific Publication
2.1 Role of anthropogenic and natural disturbance in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
A. Severe Reviewed Scientific Publication
Invasiveness
Section 2 Scoring Matrix
Total pointsScore
17-21A
11-16B
5-10C
0-4D
More than two U’sU


Total Points
16

Total Score
B
2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
A. Increases rapidly Reviewed Scientific Publication
2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
A. Increasing rapidly Observational
2.4 Innate reproductive potential
(see Worksheet A)
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
B. Moderate Reviewed Scientific Publication
2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
B. Moderate Reviewed Scientific Publication
2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
A. Frequent Reviewed Scientific Publication
2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
D. Not known anywhere else Other Published Material
3.1 Ecological amplitude/Range
(see Worksheet C)
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
A. Widespread Other Published Material
Distribution
Section 3 Scoring Matrix
Q 3.1Q 3.2Score
AA, BA
AC,D,UB
BAA
BB,CB
BDC
CA,BB
CC,DC
DAB
DB,CC
DDD
A,BUC
C,DUD
UUU


Total Score
B
3.2 Distribution/Peak frequency
(see Worksheet C)
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
D. Very low Other Published Material

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".
Short citations may be used in this table. List full citations at end of this table.

Section 1: Impact

Other Published Material B Question 1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
Identify ecosystem processes impacted:
L. duriusculum has little documentation of abiotic ecosystem impacts. However, Archbald (2011) studied the closely associated L. ramosissimum ssp. provinciale in San Francisco Bay, and found that soil moisture and salinity were decreased in some plots containing the species, but this effect was not present in all study areas. Light reduction would occur in areas with dense cover of L. duriusculum, as was observed in Carpinteria Marsh by Hubbard and Page (1997). Dense growth has also been observed in marshes in Morro Bay and San Diego County (Giessow and Sayers, pers. comms.).

Sources of information:
Archbald 2011 Hubbard and Page 1997 Giessow, J. Personal communication. Sayers, J. Personal communication.

Reviewed Scientific Publication A Question 1.2 Impact on plant community composition,
structure, and interactions
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
Identify type of impact or alteration:
Invasive sea lavenders (L. ramosissimum, L. duriusculum) have been found in about 50 acres of salt marshes throughout the San Francisco Bay in the high marsh and upland transition zones. In Carpinteria Salt Marsh, L. duriusculum was associated with decreased native plant cover over the course of 1 year, and this was attributed to L. duriusculum's ability to grow when most native plants senesce (Hubbard and Page 1997). In Marin County, L. duriusculum grows with the endangered salt marsh bird's beak (Chloropyron maritimum) and germinates earlier since it is an annual, directly competing with Birds Beak plants (Kerr, pers. comm.). In the Ocean Beach Salt Marsh, Abundance of the endangered salt marsh bird's beak is decreasing while the invasive sea lavender (Limonium duriusculum) is becoming increasingly more widespread (Goldsberry et al. 2015). Studies have shown that when sea lavenders are present the number of native salt tolerant plants decreases. The displacement of native plants such as Pacific swampfire, Marsh jaumea, and Saltgrass leads to changes in ecosystem function. Limonium duriusculum also displaces salt marsh bird's beak, a rare plant in the Morro Bay Estuary that grows in salt marshes just above the tideline, in the same habitat as the invasive sea lavender. Early detection of Limonium duriusculum is necessary to prevent its rapid spread throughout salt marsh habitat in the Morro Bay estuary (Sayers, pers.comm.).

Sources of information:
Archbald and Boyer 2014a Goldsberry et al. 2015 Hubbard and Page 1997 Kerr, D. Personal communication. Sayers, J. Personal communication.

Reviewed Scientific Publication B Question 1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
Identify type of impact or alteration:
Upper marsh habitats are important for endangered vertebrates, including Rallus longirostris obsoletus (California clapper rail) and Reithrodontomys raviventris (salt marsh harvest mouse), which rely on canopies of Grindelia stricta (gumplant), Salicornia pacifica (perennial pickleweed), and Distichlis spicata (saltgrass) either for nesting or refuge from predators, particularly during extreme high tide events. If Limonium ramosissimum or Limonium duriusculum replace these native plants, the resulting vegetation structure dominated by short basal rosettes is unlikely to provide effective cover from predators (Archbald and Boyer 2014b). In the San Francisco Bay, Morro Bay and San Diego salt marshes it forms dense patches which may alter native species use (Boyer, Sayers and Giessow, pers . comms.).

Sources of information:
Archbald and Boyer 2014b Boyer, K. Personal communication. Giessow, J. Personal communication. Sayers, J. Personal communication.

Reviewed Scientific Publication C Question 1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
Identify impacts:
Native sea lavender (L. californicum) occurs in marshes with L. duriusculum. While they do occur together there have been no studies of the potential hybridization between Limonium species which occur in California. In the Mediterranean region, over 300 endemic Limonium species have evolved, in part because of the high frequency of hybridization between members of the genus (Palacios et al. 2000). Hybridization often results in highly competitive traits and backcrossing could lead to local extirpation of the native L. californicum species, as evidenced by the ongoing Spartina alterniflora x foliosa invasion in the San Francisco Estuary (Archbald 2011).

Sources of information:
Archbald 2011 Calflora 2016 CCH 2016 Palacios et al. 2000

Section 2: Invasiveness

Reviewed Scientific Publication A Question 2.1 Role of anthropogenic and natural disturbance
in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
Describe role of disturbance:
L. duriusculum has primarily established in human- and naturally-disturbed upper salt marsh habitats. One study documented populations of L. duriusculum 2-30 km away from other populations, so the species is capable of dispersing across long distances, or multiple introductions have occurred. Two cases of accidental planting or seeding of the related. L. ramosissimum at restoration sites indicates that human-mediated dispersal may have played a role in the distributions (Archbald and Boyer 2014b). L. duriusculum has dispersed long distances in Morro Bay (Sayers, pers. comm.) indicating that it is able to disperse into natural marsh long distances without human mediation, probably by seeds floating on water. A closely related species, L. ramosissimum ssp. provinciale, is able to establish in undisturbed marsh areas (Archbald 2011). My personal observations at two sites in the south coast region indicate that this species has been included (intentionally or not) in hydroseed applications in urban edge landscaping (Vanderhoff, R., pers.comm.). Experts indicated that L. duriusculum is able to establish in disturbed and undisturbed marsh areas (Giessow, Boyer and Sayers, pers. comms.).

Sources of information:
Archbald and Boyer 2014b Archbald 2011 Boyer, K. Personal communication. Giessow, J. Personal communication. Sayers, J. Personal communication Vanderhoff, R. Personal communication.

Reviewed Scientific Publication A Question 2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe rate of spread:
Archbald (2011) found an average 2% increase in cover in the closely associated L. ramosissimum ssp. provinciale over the one year of his study, with one location increasing 12.8%. Experts indicated that L. duriusculum is able to double its population size within 10 years (Giessow, Boyer and Sayers, pers. comms.).

Sources of information:
Archbald 2011 Boyer, K. Personal communication. Giessow, J. Personal communication. Sayers, J. Personal communication.

Observational A Question 2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe trend:
L. duriusculum is increasing rapidly in the San Francisco Bay area and elsewhere (Kerr 2016 and SCWRP 2015). Experts indicated that L. duriusculum is able to double its population size within 10 years (Giessow, Boyer and Sayers, pers. comms.). Since this is reported to be the case in San Francisco Bay, Morro Bay and San Diego marshes the question is scored as increasing rapidly statewide.

Sources of information:
SCWRP 2015 Boyer, K. Personal communication. Giessow, J. Personal communication. Sayers, J. Personal communication.

Reviewed Scientific Publication B Question 2.4 Innate reproductive potential
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
Describe key reproductive characteristics:
Produces 360 to 11,400 seeds per plant; Range of seed counts from low to mid-high elevations across L. duriusculum's vertical range at Carpinteria Marsh, Santa Barbara, CA (Archbald and Boyer 2014b). Mature plants of L. ramosissimum can produce tens of thousands of floating seeds per square meter (NPS 2012). Flowers between September and June (Jepson eFlora). Hubbard and Page (1997) found no evidence of vegetative reproduction or of plants resprouting when clipped at the surface.

Sources of information:
Archbald and Boyer 2014b Hubbard and Page 1997 National Park Service 2012 Preston and McClintock, Jepson eFlora 2017.

Reviewed Scientific Publication B Question 2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
Identify dispersal mechanisms:
Human-mediated dispersal may have played a role in the distributions in San Francisco Bay due to contamination of restoration plantings (Archbald and Boyer 2014b). Hubbard and Page (1997) suggest that L. duriusculum and other Limonium spp. may have been introduced through the horticultural trade. My personal observations at two sites in the south coast region indicate that this species has been included (intentionally or not) in hydroseed applications in urban edge landscaping (Vanderhoff, R., pers.comm.). In San Diego marshes upstream sources of L. duriusculum have been found, indicating that it was planted and later escaped into the marsh. However, documentation of its sale have not yet been found as it may have been mis-identified when sold or been a contaminant growing with other species.

Sources of information:
Archbald and Boyer 2014b Hubbard and Page 1997 Giessow, J. Personal communication.

Reviewed Scientific Publication A Question 2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
Identify dispersal mechanisms:
In San Francisco Bay, a single L. duriusculum population was found ~30 km from other populations. Therefore, L. duriusculum is capable of dispersing across long distances, or multiple introductions have occurred (Archbald and Boyer 2014b). Dry flower stalks and seeds are brittle, shatter easily and float buoyantly on the water (Hubbard and Page 1997). Experts indicated that L. duriusculum is able to disperse greater than 1 km (Giessow and Sayers, pers. comms.).

Sources of information:
Archbald and Boyer 2014b Hubbard and Page 1997 Giessow, J. Personal communication. Sayers, J. Personal communication.

Other Published Material D Question 2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
Identify other regions:
L. duriusculum is native to the Mediterranean, in Spain, France and Italy (Euro + Med Plants Database). L. duriusculum is shown as occurring in Australia and New Zealand (GBIF), however the flora of New Zealand does not list it and there are no references to its behaving as an invasive in Australia. In California it has invaded coastal estuaries as far north as Sonoma County, and there is still un-invaded habitat further north, although it has already invaded marshes, riparian areas and adjacent upland grasslands (SCWRP 2015). Question is answered as D since it is not documented to be invasive anywhere but California.

Sources of information:
Euro + Med Plants Database 2016 GBIF 2016 SCWRP 2015

Section 3: Distribution

Other Published Material A Question 3.1 Ecological amplitude/Range
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
Describe ecological amplitude, identifying date of source information and approximate date of introduction to the state, if known:
The first L. duriusculum collection in CCH in California was in 2000 (CCH 2016). However, what was originally identified as L. ramosissimum in Carpinteria salt marsh in 1995 (Hubbard and Page 1997) was later re-identified as L. duriusculum (Archbald and Boyer 2014b). Callaway (1990) characterized Carpenteria salt marsh and only listed L. californicum as present, indicating an introduction date between 1990 and 1995. L. duriusculum was fist detected in Northern California in Marin County in 2007 (Archbald and Boyer 2014b). L. duriusculum occurs in California from San Francisco Bay south to San Diego County in coastal salt marshes (Calflora). It has also invaded riparian areas and adjacent upland grasslands (SCWRP 2015 and Hubbard and Page 1997). Observations in the south coast region include several in disturbed coastal sage scrub and chaparral. Frequently on hard-packed, exposed benches above alluvial soil, both in coastal and inland regions (Vanderhoff, pers. comm.).

Sources of information:
Callaway 1990 CCH 2016 Calflora 2016 Hubbard and Page 1997 SCWRP 2015 Vanderhoff, R. Personal communication.

Other Published Material D Question 3.2 Distribution/Peak frequency
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
Describe distribution:
L. duriusculum occurs in California from San Francisco Bay south to San Diego County in coastal salt marshes (Calflora).

Sources of information:
Calflora 2016 Hubbard and Page 1997 SCWRP 2015

References

List full citations for all references used in the PAF (short citations such as DiTomaso and Healy 2007 may be used in table above). Websites should include the name of the organization and the date accessed. Personal communications should include the affiliation of the person providing the observation. Enter each reference on a separate line.
Archbald, G. 2011. Predicting the spread of Limonium ramosissimum in San Francisco Bay marshes. (San Francisco State University, 2011). Archbald, G. and Boyer, K. E. 2014a. Potential for Spread of Algerian Sea Lavender (Limonium ramosissimum subsp. provinciale) in Tidal Marshes. Invasive Plant Science and Management 7, 454–463. Archbald, G., and Boyer K. E. 2014b. Distribution and Invasion Potential of Limonium ramosissimum subsp. provinciale in San Francisco Estuary Salt Marshes. San Francisco Estuary and Watershed Science. 12(2):1-22. https://escholarship.org/uc/item/61v8r7zw. Boyer, K. 2017. Personal communication from Kathy Boyer, Professor of Biology, San Francisco State University. Email received 2/9/17. Calflora. 2016. Limonium duriusculum. http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=11803. Accessed January 5, 2017. Consortium of California Herbaria (CCH). 2016. Results for search of Limonium duriusculum. http://ucjeps.berkeley.edu/consortium/index.html . Accessed January 5, 2017. Callaway, R.M., Jones S., Ferren, W.R., and Parikh, A. 1990. Ecology of a Mediterranean-climate estuarine wetland at Carpinteria, California: plant distributions and salinity in the upper marsh. Can J Bot 68(5):1139–1146. Euro + Med Plants Database. 2016. Distribution of Limonium duriusculum. http://euromed.luomus.fi/euromed_map.php?taxon=354447&size=medium. Accessed January 8, 2017. GBIF. 2016. Species page or Limonium duriusculum. http://www.gbif.org/species/7419174. Accessed January 8, 2017. Giessow, J. 2017. Personal communication with Jason Giessow, Restoration Ecologist, Program Manager, Dendra, Inc. Phone conversation and email 2/9/17. Goldsberry, D., Aziz S., and O’Shea, B. 2015. Invasion and Distribution Potential of an Invasive Sea Lavender in the Ocean Beach Salt Marsh. Creative Collaborations Undergraduate Research Conference, University of San Diego. P. 44. https://www.sandiego.edu/ugresearch/documents/CC%20URC%202015%20Abstract%20Book%20FINAL.pdf. Accessed December 13, 2016. Kerr, D. 2017. Personal communication with Drew Kerr, San Francisco Estuary Invasive Spartina Project. Phone conversation 2/2/17. Kerr, D. 2016. Cal-IPC Limonium Project Report. California Invasive Plant Council. September 2016. Hubbard, D.M. and Page, H. M. 1997. Biology and control of invasive sea lavender, Limonium ramosissimum in Carpinteria Salt Marsh, California. Report to U.S. Fish and Wildlife Service, Ventura Field Office. San Buenaventura (CA): USFWS. National Park Service, U.S. Department of the Interior, S.F. Bay Area Network, Inventory and Monitoring Program. 2012. Early Detection News. http://www.sfnps.org/download_product/3129/0 July 2012. Accessed December 13, 2016. Palacios C, Rosello JA, Gonzales-Candelas F. 2000. Study of the Evolutionary Relationships among Limonium Species (Plumbaginaceae) Using Nuclear and Cytoplasmic Molecular Markers. Molecular Phylogenetics and Evolution 14(2)232-249 Preston, R. and E. McClintock. 2017. Limonium duriusculum, in Jepson Flora project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=88826. Accessed February 15, 2017. Sayers, J. 2017. Personal communication with John Sayer, Environmental Scientist, California State Parks. Phone conversation 2/3/17. SCWRP. 2015. Invasive non-native plant Early Detection and Rapid Response (EDRR) targets in western San Diego County. http://sdmmp.com/Libraries/MonthlyCoordMtg/SD_EDRR_table_and_ID_sheets_6-22-15.sflb.ashx. Accessed December 13, 2016. Vanderhoff, R. 2017. Personal communication from Ron Vanderhoff, Roger’s Gardens Nursery. Comments on Plant Assessment Form, received January 2017.

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes, 1 points
Dense infestations produce >1,000 viable seed per square meter Yes, 2 points
Populations of this species produce seeds every year. Yes, 1 points
Seed production sustained over 3 or more months within a population annually Yes, 1 points
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 No
Total points: 5
Total unknowns: 2
Total score: B
Scoring Criteria for Worksheet A
A. High reproductive potential (6 or more points).
B. Moderate reproductive potential (4-5 points).
C. Low reproductive potential (3 points or less and less than 3 Unknowns).
U. Unknown (3 or fewer points and 3 or more Unknowns).
Note any related traits:
Return to Table 2

Worksheet B - Arizona Ecological Types is not included here


Worksheet C - California Ecological Types
 
(sensu Holland 1986)

Major Ecological Types Minor Ecological Types Code
A means >50% of type occurrences are invaded;
B means >20% to 50%;
C means >5% to 20%;
D means present but ≤5%;
U means unknown (unable to estimate percentage of occurrences invaded)
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
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
chaparralD. < 5%
Grasslands, Vernal Pools, coastal prairieD. < 5%
Meadows, and other Herbvalley and foothill grassland
CommunitiesGreat 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)
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
Return to Table 2

Addendum J - Jepson Regions Infested
 
Click here for a map of Jepson regions

Infested Jepson Regions:
Check the boxes to indicate the Jepson floristic provinces in which this species is found.














Addendum L - External Links & Resources

Calflora Plant Profile:
The Calflora Plant Profile for this species.
http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=11803
CalWeedMapper:
Load CalWeedMapper with this species already selected.