Plant Assessment Form

Limonium duriusculum

Synonyms: Statice companyonis; Limonium thiniense; Limonium duriusculum subsp. companyonis; Limonium duriusculum subsp. thiniense

Common Names: European sea lavendar

Evaluated on: 8-Jan-17

List committee review date: 26/01/2017

Re-evaluation date:

Evaluator(s)

Mona Robison/Science Program Manager
Cal-IPC
510-843-3902 ext 205
rrobison@cal-ipc.org

List commitee members

Elizabeth Brusati
Tim Hyland
Eric Wrubel
Irina Irvine
Holly Forbes
Jutta Burger
Naomi Fraga
Denise Knapp
Chris McDonald
Ron Vanderhoff
John Knapp

General Comments

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? Moderate
Alert Status? No Alert
Documentation? 3.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Other Published Material
Impact?
Four-part score BABC Total Score
B
1.2 ?Impact on plant community A. Severe Reviewed Scientific Publication
1.3 ?Impact on higher trophic levels B. Moderate Reviewed Scientific Publication
1.4 ?Impact on genetic integrity C. Minor/Low Reviewed Scientific Publication
2.1 ?Role of anthropogenic and natural disturbance in establishment A. Severe Reviewed Scientific Publication
Invasiveness?
Total Points
16 Total Score B
2.2 ?Local rate of spread with no management A. Increases rapidly Reviewed Scientific Publication
2.3 ?Recent trend in total area infested within state A. Increasing rapidly Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Reviewed Scientific Publication
2.5 ?Potential for human-caused dispersal B. Moderate Reviewed Scientific Publication
2.6 ? Potential for natural long-distance dispersal A. Frequent Reviewed Scientific Publication
2.7 ?Other regions invaded D. Not known anywhere else 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 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? B Other Published Material
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.


Question 1.2 Impact on plant community composition,
structure, and interactions?
A Reviewed Scientific Publication
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.


Question 1.3 Impact on higher trophic levels? B Reviewed Scientific Publication
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.


Question 1.4 Impact on genetic integrity? C Reviewed Scientific Publication

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
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
A Reviewed Scientific Publication
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.


Question 2.2 Local rate of spread with no management? A Reviewed Scientific Publication
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.


Question 2.3 Recent trend in total area infested within state? A Observational
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.


Question 2.4 Innate reproductive potential? B Reviewed Scientific Publication
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.


Question 2.5 Potential for human-caused dispersal? B Reviewed Scientific Publication
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.


Question 2.6 Potential for natural long-distance dispersal? A Reviewed Scientific Publication
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.


Question 2.7 Other regions invaded? D Other Published Material
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
Question 3.1 Ecological amplitude/Range? A Other Published Material

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.


Question 3.2 Distribution/Peak frequency? D Other Published Material
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


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 No
Total points: 5
Total unknowns: 2
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
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, 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)
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): B
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions