Asparagus setaceus -- California

Created by: Nicole Valentine
Created on: Monday, Jul 17th, 2023

Evaluation Summary

Asparagus setaceus (syn A. plumosus) is a perennial vine native to South Africa. It is popular in the horticultural industry, especially as a houseplant. A. setaceus reproduces by seed and rhizome; and it is dispersed by birds and humans. This species is invasive in Australia, Cuba, and New Zealand. A. setaceus forms dense thickets, ensnares trees with its vining habit, and displaces native vegetation in Australia. On horticultural sites, Asparagus species are often described as a genus or under outdated/incorrect species names.

General Evaluation Information

Date of Evaluation:

July 17, 2023

Evaluation Time (hrs):

Not Recorded

Evaluation Status:

Completed

Plant Information

Plant:

Asparagus setaceus

Plant Material:

If the plant is a cultivar, and if the cultivar's behavior differs from its parent's (behavior), explain how:

Regional Information

Region Name:

California

Climate Matching Map

These maps were built using a toolkit created in collaboration between GreenInfo Network, PlantRight, Cal-IPC, and Agricultural Sustainability Institute at UC Davis.

PRE Climate Map (external link)

Climate Matching Maps PDF:

Attachment	Size
ClimateMatch-Asparagus_setaceus-California-20230717.pdf	1.25 MB

Invasive History and Climate Matching

1. Has the species (or cultivar or variety, if applicable; applies to subsequent "species" questions) become naturalized where it is not native?

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

Asparagus setaceus is native to South Africa (CABI). It has naturalized in the US (CA, FL), eastern Australia, New Zealand, China, India, Mexico, Central America, Brazil, Uruguay, the West Indies, Pacific islands, Italy, Spain, and Portugal (GBIF; CABI).

Reference(s):

CABI (2007). CABI Invasive Species Compendium.

GBIF Backbone Taxonomy (0). Asparagus setaceus (Kunth) Jessop in GBIF Secretariat. 2023,

2. Is the species (or cultivar or variety) noted as being naturalized in the US or world in a similar climate?

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

Asparagus setaceus has been well documented as naturalized in the US (CA, FL) (GBIF). There are well documented occurrences of A. setaceus in areas of Australia, the Mediterranean that are similar to California's climate (New South Wales, southern Queensland, and Victoria) (Weeds of Australia; GBIF).

Reference(s):

Weeds of Australia (2016). Environmental Weeds of Australia.

GBIF Backbone Taxonomy (0). Asparagus setaceus (Kunth) Jessop in GBIF Secretariat. 2023,

3. Is the species (or cultivar or variety) noted as being invasive in the U.S. or world?

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Asparagus setaceus (AKA Asparagus plumosus) is listed as a weed in New South Wales, Queensland, and Western Australia (NSW Weedwise; Weeds of Australia). New South Wales Weedwise lists Asparagus setaceus as a weed of natural areas that outcompetes native plants, reduces food and habitat for native animals, smothers tree branches and causes them to fall, and forms dense mats underground that prevent other plants from germinating (NSW Weedwise). A. setaceus is also listed as invasive in Australia, New Zealand, Cuba, and on many islands in the Pacific Ocean (Weeds of Australia 2016; Environment Canterbury; Oviedo Prieto et al., 2012; CABI).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

Weeds of Australia (2016). Environmental Weeds of Australia.

R. Prieto, O., P. Oliver H., & Caluff MG. (2012). National list of invasive and potentially invasive plants in the Republic of Cuba. Bissea: Boletín sobre Conservación de Plantas del Jardín Botánico Nacional de Cuba. 6(Special Issue), 122-96.

CABI (2007). CABI Invasive Species Compendium.

Government, N. Zealand (0). Environment Canterbury Regional Council: Pest Search.

4. Is the species (or cultivar or variety) noted as being invasive in the US or world in a similar climate?

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Asparagus setaceus (AKA Asparagus plumosus) is listed as a weed in New South Wales and Queensland, Australia, which have occurrences of A. setaceus in areas of similar climate to California (NSW Weedwise). New South Wales, Australia lists Asparagus setaceus as a weed of natural areas that outcompetes native plants, reduces food and habitat for native animals, smothers tree branches and causes them to fall, and forms dense mats underground that prevent other plants from germinating (NSW Weedwise).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

5. Are other species of the same genus (or closely related genera) invasive in a similar climate?

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

There are several species in the Asparagus genus that are invasive in a similar climate. Asparagus asparagoides in invasive in California (Cal-IPC). Asparagus aethiopicus, Asparagus scandens, Asparagus africanus, Asparagus asparagoides, Asparagus falcatus are listed as invasive in New South Wales, Australia which has occurrences in areas that are a climate match to California (NSW Weedwise; GBIF).

Reference(s):

California Invasive Plant Council (2022). The Cal-IPC Inventory access 9-2022.

GBIF(Global Biodiversity Information Facility) (2021). GBIF Occurrence Download.

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?

Yes or No:

Points:

Confidence Level:

High

Answer / Justification:

Although there are many Asparagus setaceus occurrences in the California climate-matching region, most Asparagus setaceus occurrences are outside the California climate-matching region. Even in areas where there are occurrences in the California climate-matching region, there are more occurrences outside the California climate-matching region, such as Mexico, South Africa, or New South Wales, Australia. Asparagus setaceus occurs in more tropical areas than California such as Florida, Hawaii, throughout Central America, coastal Brazil, Northern coastal Argentina, coastal Uruguay, coastal Australia, India, New Zealand, Kenya, Tanzania, Malawi, Mozambique, and several islands. There are also some occurrences ouside the California climate-matching region in Northern Europe.

Reference(s):

GBIF Backbone Taxonomy (0). Asparagus setaceus (Kunth) Jessop in GBIF Secretariat. 2023,

Impact on Native Plants and Animals

7. Does this plant displace native plants and dominate (overtop or smother) the plant community in areas where it has established?

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

Asparagus setaceus is considered invasive in multiple places. In Cuba it is considered an invasive species with the capability to “transform” natural habitats (Oviedo Prieto et al., 2012). Asparagus setaceus (AKA A. plumosus) in New South Wales, Australia outcompetes native plants, smothers tree branches causing them to fall, and forms dense mats underground that prevent other plants from germinating (NSW Weedwise).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

8. Is the plant noted as promoting fire and/or changing fire regimes?

Yes or No:

Points:

Confidence Level:

Medium

Answer / Justification:

There is no reported evidence of Asparagus setaceus changing fire regimes. Asparagus setaceus is a wiry branching vine that invades rainforest vegetation by climbing into the forest canopy and smothering trees (NSW Weedwise). Stems can be woody when older (NSW Weedwise). Although it can form dense mats, its wiry growth habit makes it seem unlikely that it would change fire regimes.

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

9. Is the plant a health risk to humans or animals/fish? Has the species been noted as impacting grazing systems?

Yes or No:

Points:

Confidence Level:

Medium

Answer / Justification:

Asparagus setaceus is unlikely to be a health risk. Asparagus setaceus berries are poisonous if eaten by humans and dogs and cats (NCSU). There is no evidence of the berries poisoning people or wildlife in the wild. Although Asparagus setaceus reduces food and habitat for native animals but unsure if this includes fish or nonnative grazing animals (NSW Weedwise). Asparagus setaceus is unlikely to occur in rangelands, so its impact on grazing animals is unlikely. Asparagus setaceus may cause irritation due to its sharp thorns along the stem and its needle-like leaves complicate control efforts (UF IFAS, NCSU). There are no reports of Asparagus setaceus posing a health risk other than potentially causing skin irritation.

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

North Carolina State University (2014). North Carolina State University Cooperative Extension.

University of Florida Center for Aquatic & Invasive Plants (0). Center for Aquatic and Invasive Plants \textbar University of Florida, IFAS.

10. Does the plant produce impenetrable thickets, blocking or slowing movement of animals, livestock, or humans?

Yes or No:

Yes

Points:

Confidence Level:

Medium

Answer / Justification:

Asparagus setaceus is wiry, perennial climber with stems up to 5 m or more long (Weeds of Australia). A. seteaceus smothers tree branches and causes them to fall, and forms dense mats underground that prevent other plants from germinating (NSW Weedwise). Asparagus setaceus has sharp thorns along the stem and needle-like leaves which complicate control efforts (UF IFAS, NCSU). Although A. setaceus is wiry, its vining habit, dense matting tendencies, thorns, and its ability to bring trees down make it likely to impact movement.

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

Weeds of Australia (2016). Environmental Weeds of Australia.

University of Florida Center for Aquatic & Invasive Plants (0). Center for Aquatic and Invasive Plants \textbar University of Florida, IFAS.

North Carolina State University (2014). North Carolina State University Cooperative Extension.

Reproductive Strategies

11. Does this species (or cultivar or variety) reproduce and spread vegetatively?

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Asparagus setaceus can spread vegetatively. Asparagus setaceus has roots that consist of a central crown made up of a cluster of rhizomes (NSW Weedwise). One must remove the entire crown and underground stem to prevent regrowth (IFAS).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

University of Florida Center for Aquatic & Invasive Plants (0). Center for Aquatic and Invasive Plants \textbar University of Florida, IFAS.

12. If naturally detached fragments from this plant are capable of producing new plants, is this a common method of reproduction for the plant?

Yes or No:

Points:

Confidence Level:

Medium

Answer / Justification:

Although Asparagus setaceus spreads mostly by seed, A. setaceus can spread from root fragments and has a vine growth habit (Weeds of Australia, NSW Weedwise). Root fragments have been spread by dumping of green waste and contaminated machinery or vehicles (NSW Weedwise). Because these cases of spreading seem to be restricted to garden cases, this may not occur naturally as a common method of reproduction. However, it is noted that in New Zealand the vegetative spread of A. setaceus by root fragments can be aided by water and soil movement (Environment Canterbury).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

Government, N. Zealand (0). Environment Canterbury Regional Council: Pest Search.

13. Does the species (or cultivar or variety) commonly produce viable seed?

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Asparagus setaceus reproduces mostly by seed (NSW Weedwise).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

14. Does this plant produce copious viable seeds each year (> 1000)?

Yes or No:

Points:

Confidence Level:

Very Low

Answer / Justification:

There was not enough data for me to answer this question. The Asparagus species were often lumped together or not distinguished on horticultural sites, so I was not able to determine whether Asparagus setaceus produced over 1000 viable seeds per year. Asparagus setaceus flowers are produced singly or in pairs in the forks of the scale leaves along the short lateral branches (Weeds of Australia). Seeds are often solitary but up to 3 per fruit (NSW Weedwise).

Reference(s):

Weeds of Australia (2016). Environmental Weeds of Australia.

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

15. Is there significant germination (>25%) of seeds the next growing season, with no requirement of an infrequent environmental condition for seeds to germinate (i.e. fire) or long dormancy period?

Yes or No:

Points:

Confidence Level:

High

Answer / Justification:

Asparagus setaceus seed had an 83% germination rate under the following conditions: substrate was kept constantly moist, a temperature of 79°F, and 70% relative humidity. (Maciel et al 1999). Additionally, horticultural sites recommend that asparagus setaceus seeds germinate best when soaked in a bowl of warm water for 24 hours before sowing and take three to four weeks to germinate (Easy Grow Seeds, True Leaf Market). These accounts suggest that Asparagus setaceus germinates best in warm, humid environments which are not frequent environmental conditions in California.

Reference(s):

Market, T. Leaf (0). True Leaf Market.

Easy Grow Seeds (0). Easy Grow Seeds.

Maciel, N., Mogollón N., & Mendoza A. (1999). Germination and emergence of four cut foliage Asparagus. Journal of the Faculty of Agronomy of the University of Zulia, Institute of Agronomic Research.

16. Does this plant produce viable seed within the first three years (for an herbaceous species) to five years (for a woody species) after germination?

Yes or No:

Yes

Points:

Confidence Level:

Medium

Answer / Justification:

Asparagus setaceus is one of the fastest growing houseplants (NCSU). Plumosa Asparagus ferns are quick to mature in 49-63 days as 18-24 inch tall shrubby mounds with a 24-36 inch spread of lace-like ferns (True Leaf Market).

Reference(s):

North Carolina State University (2014). North Carolina State University Cooperative Extension.

Market, T. Leaf (0). True Leaf Market.

17. Does this plant continuously produce seed for >3 months each year or does seed production occur more than once a year?

Yes or No:

Yes

Points:

Confidence Level:

Medium

Answer / Justification:

Asparagus setaceus is reported to flower for over three months. Asparagus setaceus flowers from April through September in California (Calflora). A. setaceus has flowers present from early spring to early autumn in Australia (NSW Weedwise).

Reference(s):

Calflora (0). Calflora: Plant Search.

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

Dispersal

18. Are the plant’s propagules frequently dispersed long distance (>100 m) by mammals or birds or via domestic animals?

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Berries are dispersed by birds (IFAS, NSW Weedwise).

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

University of Florida Center for Aquatic & Invasive Plants (0). Center for Aquatic and Invasive Plants \textbar University of Florida, IFAS.

19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?

Yes or No:

Points:

Confidence Level:

Medium

Answer / Justification:

No evidence of seeds frequently dispersing by wind or water. Seeds are contained within a fleshy fruit (NSW Weedwise). This makes it unlikely that seed will spread by wind.

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

20. Are the plant’s propagules frequently dispersed via contaminated seed (agriculture or wildflower packets), equipment, vehicles, boats or clothing/shoes?

Yes or No:

Yes

Points:

Confidence Level:

Medium

Answer / Justification:

Asparagus setaceus has several mechanisms by which it can disperse through human contact. Root fragments are spread by dumping of green waste, deliberate planting in gardens, and contaminated machinery or vehicles (NSW Weedwise). Seeds are also spread through green waste (Weeds of Australia). Although it is not reported how frequently this dispersal occurs, this species is likely to come into regular contact with humans and has mechanisms by which it can disperse.

Reference(s):

NSW Department of Primary Industries, Primary Industries Agriculture, New South Wales Department of Primary Industries (2014). NSW Weedwise.

Weeds of Australia (2016). Environmental Weeds of Australia.

Evaluation Notes

Q12. Keptep going back and forth on how to answer. There do not seem to be concrete examples of root fragments spreading but it was suggested as occurring however I could not tell if this was a common occurrence.

CABI:
https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.7409
Accessed 11/15/2023

Calflora:
https://www.calflora.org/app/taxon?crn=9025
Accessed 11/15/2023

Environment Canterbury:
https://www.ecan.govt.nz/pest-search/asparagus-fern/#:~:text=Asparagus%2....
Accessed 11/15/2023

GBIF:
https://www.gbif.org/species/2768686
Accessed 11/15/2023

NCSU Extension:
https://plants.ces.ncsu.edu/plants/asparagus-plumosus/
Accessed 11/15/2023

NSW Weedwise:
https://weeds.dpi.nsw.gov.au/Weeds/Climbingasparagusfern#:~:text=Climbin...(Asparagus%20plumosus)&text=Climbing%20asparagus%20fern%20is%20a,forest%20canopy%20and%20smothering%20trees.
Accessed 11/15/2023

UF IFAS:
https://plants.ifas.ufl.edu/plant-directory/asparagus-setaceus/#:~:text=....
Accessed 11/15/2023

Weeds of Australia:
https://keyserver.lucidcentral.org/weeds/data/media/Html/asparagus_plumo...
Accessed 11/15/2023

Total PRE Score