Plant Assessment Form

Asparagus asparagoides

Synonyms: Myriophyllum asparagoides, Asparagus medeoloides, Dracaena medeoloides, Elachanthera sewelliae, Luzuriaga sewelliaea, Medeola asparagoides

Common Names: bridal creeper; African asparagus fern; ornamental asparagus; smilax asparagus

Evaluated on: 1/24/05

List committee review date: 08/07/2005

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, project manager
California Invasive Plant Council
1442A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.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? Moderate
Alert Status? Alert
Documentation? 2.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Reviewed Scientific Publication
Impact?
Four-part score BACD Total Score
B
1.2 ?Impact on plant community A. Severe Other Published Material
1.3 ?Impact on higher trophic levels C. Minor Observational
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Reviewed Scientific Publication
Invasiveness?
Total Points
13 Total Score B
2.2 ?Local rate of spread with no management U. Unknown
2.3 ?Recent trend in total area infested within state U. Unknown
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Other Published Material
2.5 ?Potential for human-caused dispersal B. Moderate Other Published Material
2.6 ? Potential for natural long-distance dispersal A. Frequent Reviewed Scientific Publication
2.7 ?Other regions invaded A. Invades 3 or more ecological types Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
D. Narrow Other Published Material
Distribution?
Total Score D
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? B Reviewed Scientific Publication
Identify ecosystem processes impacted:

Dense stems limit light levels (1). Dies back in the summer, leaving a blanket of entwined stems that can be a fire hazard.


Sources of information:

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

Outcompetes other vegetation (1). Shoots form a dense canopy which shades shrubs, herbs, and seedlings. The tuber mat forms a thick barrier just below the surface which limits the access of other plants to soil moisture and nutrients. 87% of the plant weight is below ground when it is actively growing (2). Data from Australian literature. No information available from California. It is expected that a similar situation would occur in California if the species became well established.


Sources of information:

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

Native vegetation germination and dispersal is reduced by A. asparagoides, but no direct evidence on other tropic levels known in California. Displacement of native vegetation has effects on wildlife.. Frugivorous birds disperse A. asparagoides fruits, therefore competing with native vegetation for avian dispersal and germination.


Sources of information:

Stansbury and Scott 1999
John Knapp, Catalina Conservancy, Avalon, CA. Per. obs.


Question 1.4 Impact on genetic integrity? D Other Published Material

none No native Asparagus spp.


Sources of information:

Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA enter text here


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

Occurs as a weed along roadsides, waste places, and other disturbed areas near towns. However, it is generally not found in open areas and can tolerate heavy shade (1).Roadsides, gardens, and woodlands have been invaded, as well as extensive areas of crop lands. Undisturbed native habitats are invaded. A. asparagoides can germinate in a wide range of environmental conditions (2).


Sources of information:

1. Parsons and Cuthbertson 2001
2. Stansbury and Scott 1999


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

Peak spread in Australia was 0.6m/yr of radial spread for patches of 10 square m. In southwest Australia, A. asparagoides has been observed to spread kilometers per year. It is widespread and highly invasive in Australia. No information available in California.


Sources of information:

1. Stansbury and Scott 1999.


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

no information


Sources of information:

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

Perennial, erect or climbing herb. Seeds germinate in autumn or early winter. Plants become dormant over the summer. Roots can survive long droughts and resprout when rains come. Reproduces by seed, tuber, and rhizome. Seed is believed to be viable in California. Many seeds are produced per plant, and has a high fecundity. Seed remains persistant for 2-3 years if buried. Bud bank resprouts after disturbance such as fire and mowing. Time to reproductive maturity occurs between 2-3 years. In Australia, seed production occurs for two months. Information based on Australian literature.


Sources of information:

1. Parsons, W. T., and E. G. Cuthbertson. 2001. Noxious weeds of Australia. 2nd edition. CSIRO Publishing. Collingwood, VIC, Australia.
Willis, A.J., McKay, R., Vranjic, J.A., Kilby, M.J., and Groves, R.H. 2003. Comparative seed ecology of the engangered shrub, Pimelea spicata and the threatening weed, bridal creeper: smoke, heat and other fire-related germination cues. Ecological Management and Restoration 4(1): 55-65.
Brown, K. and Brooks, K. 1996. Bushland Weeds: a practical guide to their management with cases studies from the Swan Coastal Plain and beyond. Environmental Weeds Action Network. Pp. 52-52.
Stansbury, C. Observations of birds feeding on bridal creeper (Asparagus asparagoides) fruits within Yanchep National Park, Western Australia. Plant Protection Quarterly. 11(2): 59-60.
Stansbury, C.D. 2001. Dispersal of the environmental weed bridal creeper, Asparagus asparagoides, by silvereyes, Zosterops lateralis, in south-western Australia. Emu 101(1): 39-45.
Giessow, J. 2001. Plants of Potential Concern Asparagus asparagoides. California Exotic Pest Plant Council News. 9(1):7-8.


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

Spread by dumped garden refuse (1) or by seeds adhering to animals, clothing, and machinery (2). On Catalina Island, A. asparagoides is commonly seen growing out of holes created by acorn wood peckers in Phoenix palms in the town of Avalon (3).


Sources of information:

1. Stansbury and Scott 1999
2. Parsons and Cuthbertson 2001
3. Knapp, J.J. Personal observations from 2001-2004 on Catalina Island, CA. (310) 510-1299, jknapp@catalinaconservancy.org.


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

Dispersed by frugivorous birds (up to 12 km in Australia) (1). Also dispersed by water. In an Australian study, 93% of bridal creeper occurrences were within 500m of drainage or watercourses (2). Rabbits and foxes can eat and disperse fruits and seeds (3).


Sources of information:

1. Stansbury, C. D. 2001. Dispersal of the environmental weed Bridal Creeper, Asparagus asparagoides, by Silvereyes, Zosterops lateralis, in south-western Australia. Emu 101(1): 39-45
2. Pigott, J. P. and P. Farrell. 1996. Factors affecting the distribution of bridal creeper (Asparagus asparagoides) in the lower south-west of Western Australia. Plant Protection Quarterly 11(2): 54-56
3. Anonymous 2000.


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

Native to South Africa. Considered a noxious weed in Australia, where it invades coastal vegetation, wet and dry schlerophyll forests, heathlands, mallee shrublands, and riparian areas (1), as well as jarrah forest, and low woodland, and Eucalyptus stands (2). USDA does not list it in any other US state.


Sources of information:

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

Invades disturbed areas and fields (1) in Alameda, Santa Barbara, and San Diego counties (2). Invades riparian areas in southern California (3).


Sources of information:

1. DiTomaso, J., and E. Healy. in prep. Weeds of California and Other Western States.
2. USDA, NRCS. 2004. The PLANTS Database, Version 3.5 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA
3. Giessow, J. 2000. Plants of Potential Concern Asparagus asparagoides. California Exotic Pest Plant Council News. Winter.


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

Very uncommon in California.


Sources of information:

Observational, DiTomaso.


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Unknown
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually No
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 Yes
Fragments easily and fragments can become established elsewhere Yes
Resprouts readily when cut, grazed, or burned Yes
Total points: 6
Total unknowns: 3
Total score: A?

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 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 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): D
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions

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