Oncosiphon piluliferum_Ron Vanderhoff
Photo by Ron Vanderhoff

Oncosiphon piluliferum Risk Assessment

Common names: globe chamomile

Oncosiphon piluliferum -- California

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Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
March 18, 2016
Evaluation Time (hrs): 
2 Hours
Evaluation Status: 
Completed
Plant Information
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: 
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.
Climate Matching Maps PDF: 
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: 
1
Confidence Level: 
Very High
Answer / Justification: 
Naturalized in California and Arizona. Adventive (possibly naturalizing) in Victoria, Australia.
Reference(s): 
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: 
2
Confidence Level: 
Very High
Answer / Justification: 
Naturalized in six counties in California as well as Arizona and Australia. In California, present in coastal scrub, chaparral, and disturbed sites. In Western Australia, naturalized in valleys, near salt lakes, along track edges, in disturbed woodlands & agricultural sites.
Reference(s): 
3. Is the species (or cultivar or variety) noted as being invasive in the U.S. or world?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
High
Answer / Justification: 
Randall 2012 has several notations of it being naturalized, and one note of it as an environmental weed in Victoria, Australia, but the Victorian weeds website does not list it. This plant is highly invasive in some state parks in southern California, and is probably under-reported in those and elsewhere. It occurs in Torrey Pines SNR as well as San Pasqual Battlefield SHP. There is anecdotal evidence that it was moved between parks with equipment or fill material. It also is abundant in part of Lake Perris SRA, in an old ag field. There were plans to do some management there but am not sure if it happened.- Mona Robison
Reference(s): 
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: 
3
Confidence Level: 
High
Answer / Justification: 
Randall 2012 has several notations of it being naturalized, and one note of it as an environmental weed in Victoria, Australia, but the Victorian weeds website does not list it. This plant is highly invasive in some state parks in southern California, and is probably under-reported in those and elsewhere. It occurs in Torrey Pines SNR as well as San Pasqual Battlefield SHP. There is anecdotal evidence that it was moved between parks with equipment or fill material. It also is abundant in part of Lake Perris SRA, in an old ag field. There were plans to do some management there but am not sure if it happened.- Mona Robison
Reference(s): 
5. Are other species of the same genus (or closely related genera) invasive in a similar climate?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
Several other species in synonym genus Matricaria are listed by Randall 2012. Pineapple weed (Chamomilla suaveolens, syn. to Matricaria discoides) is a weed of crops, gardens, etc.
Reference(s): 
6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
High
Answer / Justification: 
The locations in GBIF are California, Arizona, South Africa, and the SE and SW coasts of Australia. Most of these locations match California. GBIF map = http://www.gbif.org/species/3118650
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: 
1
Confidence Level: 
High
Answer / Justification: 
This plant is highly invasive in some state parks in southern California, and is probably under-reported in those and elsewhere. It occurs in Torrey Pines SNR as well as San Pasqual Battlefield SHP. There is anecdotal evidence that it was moved between parks with equipment or fill material. It also is abundant in part of Lake Perris SRA, in an old ag field. There were plans to do some management there but am not sure if it happened. - Mona Robison
Reference(s): 
8. Is the plant noted as promoting fire and/or changing fire regimes?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
Cannot find any information on this so defaulting to no.
Reference(s): 
9. Is the plant a health risk to humans or animals/fish? Has the species been noted as impacting grazing systems?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Used as a medicinal plant to treat fevers and other ailments.
Reference(s): 
10. Does the plant produce impenetrable thickets, blocking or slowing movement of animals, livestock, or humans?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Grows 15-45 (sometimes 70)cm tall so unlikely to produce a stand that would be considered impenetrable.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
No indication of vegetative reproduction.
Reference(s): 
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: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
No indication of vegetative reproduction.
Reference(s): 
13. Does the species (or cultivar or variety) commonly produce viable seed?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Produces seeds.
Reference(s): 
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
Points: 
Confidence Level: 
Very Low
Answer / Justification: 
No information
Reference(s): 
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: 
Very Low
Answer / Justification: 
no information
Reference(s): 
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: 
1
Confidence Level: 
Very High
Answer / Justification: 
An annual herb.
Reference(s): 
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: 
1
Confidence Level: 
Medium
Answer / Justification: 
Flowers March to July in California. I am extrapolating this to more than three months.
Reference(s): 
Dispersal
18. Are the plant’s propagules frequently dispersed long distance (>100 m) by mammals or birds or via domestic animals?
Yes or No: 
No
Points: 
0
Confidence Level: 
Very Low
Answer / Justification: 
No information.
Reference(s): 
19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?
Yes or No: 
No
Points: 
0
Confidence Level: 
Very Low
Answer / Justification: 
No information.
Reference(s): 
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: 
1
Confidence Level: 
Medium
Answer / Justification: 
No information on this species but other species of synonym genus Matricaria are spread by attaching to vehicles or by other human activities so I am inferring that this species could be spread the same way. There is anecdotal evidence that it was moved between state parks with equipment or fill material. - Mona Robison
Reference(s): 
Evaluation Notes

A project in San Diego evaluated this species' impact in their area: http://sdmmp.com/management/PlantAssessmentForms.aspx

Jepson eFlora: http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=80983

Florabase: https://florabase.dpaw.wa.gov.au/browse/profile/20660

A journal literature search found only four references, one noting this species from riparian habitats in Southern California.  Native to South Africa, but there is no information on the PlantzAfrica (South African native plants) website.

Reviewed by Barbara Castro, CA Dept of Water Resources, and Mona Robison, independent botanist

Total PRE Score

  • < 13 : accept (low risk of invasiveness)
  • 13 - 15 : evaluate further
  • > 15 : reject (high risk of invasiveness)

PRE Score: 
16
Number of questions answered: 
18
Screener Confidence (%): 
70.0
PRE Content Access and Privacy
Evaluation visibility: 
Public - accessible to all site users

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