Chasmanthe floribunda_Tony Morosco
Photo by Tony Morosco

Chasmanthe floribunda Risk Assessment

Common names: African cornflag

Chasmanthe floribunda -- California

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Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
June 10, 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 Australia - New South Wales, - South Australia, - Victoria, - Western Australia New Zealand, California
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 14 counties along the California coast. Some of the locations along the Australian southern coast have similar climate to California. Widely naturalized in Australia where it is a weed of roadsides, disturbed sites, waste areas, parks, grasslands, open woodlands, coastal sites and waterways (i.e. riparian vegetation) in temperate regions. See direct links in Evaluation Notes.
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: 
Very High
Answer / Justification: 
Forms dense clumps, invading grassland and bushland in southeastern Australia (Richardson et al.). African cornflag (Chasmanthe floribunda ) is a significant environmental weed in Victoria, South Australia and Western Australia. It is also regarded as a minor environmental weed or sleeper weed in Tasmania and New South Wales (Queensland Biosecurity). Weeds of California and Other Western States lists it as an uncommon ornamental escape in urban disturbed areas in California.
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: 
Very High
Answer / Justification: 
Forms dense clumps, invading grassland and bushland in southeastern Australia (Richardson et al.). Based on locations in the Australian herbarium, I believe these include areas similar to California. African cornflag (Chasmanthe floribunda ) is a significant environmental weed in Victoria, South Australia and Western Australia. It is also regarded as a minor environmental weed or sleeper weed in Tasmania and New South Wales. Most of the observation descriptions in Calflora appear to be along trails or roads.
Reference(s): 
5. Are other species of the same genus (or closely related genera) invasive in a similar climate?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
Several other Chasmanthe species are listed in Randall 2012 but most of the references are only as naturalized or as "potential environmental weeds". No information on impacts. Richardson et al. says that Chasmanthe bicolor is a prolific seeder in southeast Australia and has great environmental weed potential.
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: 
Very High
Answer / Justification: 
C. floribunda's native range, as well as many of the areas where it has naturalized, have a similar climate to California. Native range in South Africa: Restricted to the coastal and near-inland parts of the winter-rainfall zone of South Africa, extending from coastal Namaqualand in the Northern Cape, south to the Cape Peninsula and east to Hermanus in the Western Cape, most commonly on rocky outcrops along the coast and along the coastal mountains, favouring sandstone and granite soils, but in dolerite outcrops near Nieuwoudtville. The species requires cool temperate growing conditions with moderate watering in winter, and dry or well-drained soils during the summer dormant period.
Reference(s): 
South African National Biodiversity Institute (2012).  Plantz Africa.
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: 
Very High
Answer / Justification: 
Forms dense clumps, invading grassland and bushland in southeastern Australia (Richardson et al.). Considered a serious weed in some parts of Australia as described above. Weber 2003 says it builds up large, dense populations that eliminate native vegetation. From Queensland: "This garden escape often becomes naturalised along roadsides and in waste areas, from where it spreads into urban bushland, open woodlands and grasslands. These populations are thought to represent a serious threat to grassy woodlands, dry and damp sclerophyll forests and riparian vegetation in Victoria and throughout south-western Western Australia."
Reference(s): 
8. Is the plant noted as promoting fire and/or changing fire regimes?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Did not find information on this but am assuming no because its characteristics are not those that seem likely to affect fire regimes.
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: 
No mention of toxicity in ornamental references. While it does invade grasslands in Australia, I do not have any specific information on impacts to grazing areas.
Reference(s): 
South African National Biodiversity Institute (2012).  Plantz Africa.
10. Does the plant produce impenetrable thickets, blocking or slowing movement of animals, livestock, or humans?
Yes or No: 
No
Points: 
0
Confidence Level: 
Very High
Answer / Justification: 
I have observed this plant in disturbed urban areas and it does not seem capable of producing impenetrable thickets. It has thin, pliable leaves that grow 2 ft tall, with the flower spikes extending another foot.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
A member of the Iris family that reproduces by corms, which we're counting as 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: 
Reproduces by corms. I'm not sure if this counts as detached fragments but am answering as no as it does not fit the definition of a vine habit or reproducing from nodes as mentioned in the question instructions.
Reference(s): 
13. Does the species (or cultivar or variety) commonly produce viable seed?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Seeds up to 12 per capsule, globose or somewhat angled by pressure, ± 5 mm in diameter, bright orange, coat hard and shiny.
Reference(s): 
South African National Biodiversity Institute (2012).  Plantz Africa.
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
Flower spikes each produce 30-40 flowers in South Africa (Sunset Book says 12-28 flowers for California). Up to 12 seeds per capsule, but not stated how many capsules per flower. Assuming 40x12 seeds would not exceed 1000 per plant.
Reference(s): 
South African National Biodiversity Institute (2012).  Plantz Africa.
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: 
Answer / Justification: 
According to Sunset, corms multiply rapidly and in a garden setting should be divided every 2-3 years. Plants die back each year but regrow with the first winter rains. However, that reproduction is probably mostly from the corms. Unsure of answer.
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: 
Points: 
Confidence Level: 
Answer / Justification: 
No information.
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: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Flowers July-September in native range in South Africa. Calflora lists California bloom time as Feb - May. I'm going to be conservative and say that seeds are not produced more than three months.
Reference(s): 
South African National Biodiversity Institute (2012).  Plantz Africa.
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: 
1
Confidence Level: 
High
Answer / Justification: 
The seeds and corms are spread in dumped garden waste and contaminated soil. The seeds are also dispersed by birds and water.
Reference(s): 
19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
The seeds and corms are spread in dumped garden waste and contaminated soil. The seeds are also dispersed by birds and water.
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: 
High
Answer / Justification: 
The seeds and corms are spread in dumped garden waste and contaminated soil. The seeds are also dispersed by birds and water.
Reference(s): 
Evaluation Notes

Reviewed by Gina Darin, CA Dept of Water Resources, and Irina Irvine, NPS Santa Monica Mountains National Recreation Area

 

USDA GRIN: https://npgsweb.ars-grin.gov/gringlobal/taxonomydetail.aspx?id=10154

Australia Virtual Herbarium: http://avh.ala.org.au/occurrences/search?taxa=chasmanthe+floribunda#tab_...

Queensland: http://keyserver.lucidcentral.org/weeds/data/media/Html/chasmanthe_flori...

Calflora: http://www.calflora.org/entry/observ.html#srch=t&taxon=Chasmanthe+florib...

South Africa: http://pza.sanbi.org/chasmanthe-floribunda

A journal literature search brought up only 6 articles, none of which seemed helpful to this evaluation.

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 (%): 
86.7
PRE Content Access and Privacy
Evaluation visibility: 
Public - accessible to all site users

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