Enchylaena tomentosa R. Br.; Ruby saltbush

California Pest Rating for
Enchylaena tomentosa R. Br.; Ruby saltbush
Chenopodiaceae: Caryophyllales
Pest Rating: A  |  Proposed Seed Rating: R

 


PEST RATING PROFILE
Initiating Event:

The species was detected in San Diego County in 2014 and given a “Q” rating.

History & Status:

Ruby saltbush is an open, straggling shrub native to Australia that can grow up to 2 m tall and wide, but is usually much shorter. Grazing and low nutrient soils in full sun limit the height of the plant, but it is quite capable of clambering over adjacent vegetation. Leaf color in California specimens is dark blue-green. The leaves are succulent, 1-2 cm long, cylindrical, and may be hairy or smooth. Stems are distinctively marked with parallel lines. The flowers are small, occurring in the leaf axils. The sepals become fleshy and red when the fruit ripens, simulating a juicy berry.

Official Control: Ruby saltbush has not been subjected to official control.

California DistributionRuby saltbush is known from a single infestation in Central San Diego County, California. The plants grow along a sloping road bank and an adjacent arroyo surrounded by residential development. As other vegetation along the road bank may be horticultural in origin, it seems likely that the plant was planted intentionally as a novel, low maintenance landscape shrub. The oldest known specimen in California was collected in 2014.

California Interceptions: Vouchered specimens are known from San Diego County, although they have not yet been accessioned.

United States:  Ruby saltbush is known only from California in the United States.

International: Ruby saltbush is native to Australia, where it is widely distributed in arid and semiarid areas in various shrubby or grassland plant communities. It is especially common in slightly saline soils. It is reported as naturalized in New Caledonia.

The risk Ruby saltbush would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: The plant occurs in grassland and coastal scrub. It is spreading in ruderal areas near the coast. It is tolerant of slightly saline soils. Therefore, its adaptation to coastal habitats in southern California is likely high. It scores as Medium (2) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California. Score:

-Low (1) Not likely to establish in California; or likely to establish in very limited areas.

-Medium (2) may be able to establish in a larger but limited part of California.

-High (3) likely to establish a widespread distribution in California.

2) Host Range: Risk is High (3) as weeds do not require any one host, but grow wherever ecological conditions are favorable.

Evaluate the host range of the pest. Score:

-Low (1) has a very limited host range.

-Medium (2) has a moderate host range.

-High (3) has a wide host range.

3) Pest Dispersal Potential: Ruby saltbush produces numerous red, fleshy fruits that are typical of bird-dispersed woody plants. Hundreds to the low 1000s of fruits are produced by a mature shrub. Ruby saltbush receives a Medium (2) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

-Low (1) does not have high reproductive or dispersal potential.

-Medium (2) has either high reproductive or dispersal potential.

-High (3) has both high reproduction and dispersal potential.

4) Economic Impact: It has not yet had an impact on agricultural lands and future possible impacts are unknown. Ruby saltbush is browsed by livestock under adverse conditions, but its range value is not high. It receives a Low (1) in this category.

Evaluate the economic impact of the pest to California using the criteria below. Score:

A. The pest could lower crop yield.

B. The pest could lower crop value (includes increasing crop production costs).

C. The pest could trigger the loss of markets (includes quarantines).

D. The pest could negatively change normal cultural practices.

E. The pest can vector, or is vectored, by another pestiferous organism.

F. The organism is injurious or poisonous to agriculturally important animals.

G. The organism can interfere with the delivery or supply of water for agricultural uses.

-Low (1) causes 0 or 1 of these impacts.

-Medium (2) causes 2 of these impacts.

-High (3) causes 3 or more of these impacts.

5) Environmental Impact: Ruby saltbush is overgrowing adjacent vegetation such as jojoba and prickly pear cactus; it is dense and its sprawling stems can smother other plants. In adjacent areas it is growing as scattered plants that may be suppressing other coastal scrub species through competition. Rare taxa that might be affected include strand species such as creeping lotus (Acmispon prostratus) and coastal scrub species such as California gnatcatcher (Polioptila californica). Because it forms dense patches, Ruby saltbush could interfere with recreation along the coast. Ruby saltbush receives a High (3) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.

B. The pest could directly affect threatened or endangered species.

C. The pest could impact threatened or endangered species by disrupting critical habitats.

D. The pest could trigger additional official or private treatment programs.

E. The pest could significantly impact cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score:

-Low (1) causes none of the above to occur.

-Medium (2) causes one of the above to occur.

-High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Ruby saltbush: Medium (11)

Add up the total score and include it here.

-Low = 5-8 points

Medium = 9-12 points

-High = 13-15 points

6) Post Entry Distribution and Survey Information: Ruby saltbush has been found in in 1 locality in California; This may have spread from cultivation. It receives a Low (-1) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

-Not established (0) Pest never detected in California, or known only from incursions.

Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).

-Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.

-High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (10)

Uncertainty:

This plant is showing the ability to spread in disturbed areas near the coast. Its future potential impact on agriculture, if allowed to spread, is unknown.

Conclusion and Rating Justification:

This plant is just beginning its spread in California. It shows tendencies of invasiveness and it is strictly limited in distribution now. The probability of eradication is high. It should be given a rating of “A” to encourage attention to this plant.

References:

Calflora; Enchylaena tomentosa. Accessed 2/22/2015:                            http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=13047

Florabase; Enchylaena tomentosa. Accessed 2/22/2015: http://florabase.dpaw.wa.gov.au/browse/profile/2511

USDA Plants Database, Enchylaena tomentosa. Accessed 2/22/2015: http://plants.usda.gov/core/profile?symbol=ento3

Western Australia Department of Agriculture; ruby salt bush. Accessed 2/22/2015: https://www.agric.wa.gov.au/ruby-saltbush

Responsible Party:

Dean G. Kelch, Primary Botanist; California Department of Food and Agriculture; 1220 N Street, Sacramento, CA 95814; Tel. (916) 654-0312; plant.health[@]cdfa.ca.gov.


Comment Period: CLOSED

The 45-day comment period opened on Monday , October 19, 2015 and closed on December 3, 2015.


Pest Rating: A  |  Proposed Seed Rating: R


Posted by ls