Kniphofia uvaria by Toby Hudson
Photo by Toby Hudson

Kniphofia uvaria Risk Assessment

Common names: redhot poker

Kniphofia uvaria -- California

Primary tabs

Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
October 1, 2016
Evaluation Time (hrs): 
3 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: 
High
Answer / Justification: 
Naturalized in California in 11 counties according to Calflora. Also Naturalised in some parts of south-eastern Australia (i.e. on the central and southern tablelands of New South Wales and in southern Victoria). Possibly also naturalised in south-eastern South Australia (Queensland Government) as well as New Zealand, Europe, Central and South America (GBIF).
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: 
High
Answer / Justification: 
Naturalized in California in 11 counties according to Calflora. Also Naturalised in some parts of south-eastern Australia (i.e. on the central and southern tablelands of New South Wales and in southern Victoria). Possibly also naturalised in south-eastern South Australia (Queensland Government) as well as New Zealand, Europe, Central and South America (GBIF). Some of the areas where K. uvaria occurs in Australia match the climate of California based on the Cal-IPC climate map.
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: 
K. uvaria is listed in Randall (2012) as an environmental weed or as naturalized. It is considered an environmental weed in Australia, and has spread into natural areas where it forms thick clumps of vegetation and threatens sensitive ecosystems (Victorian and Queensland Government).
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: 
K. uvaria is listed in Randall (2012) as an environmental weed or as naturalized. It is considered an environmental weed in Australia, and has spread into natural areas where it forms thick clumps of vegetation and threatens sensitive ecosystems (Victorian and Queensland Government). Some of the areas where it occurs in Australia match the climate of California based on the Cal-IPC climate map.
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: 
High
Answer / Justification: 
The species of Kniphofia in Randall (2012), other than K. uvaria, are listed as naturalized or weeds, not as environmental weeds, invasive or noxious.
Reference(s): 
6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?
Yes or No: 
No
Points: 
0
Confidence Level: 
High
Answer / Justification: 
Almost all of the areas outside California where K. uvaria occurs do not match the climate of California according to the Cal-IPC climate map.
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: 
Medium
Answer / Justification: 
In Australia, K. uvaria is considered an environmental weed and has spread into natural areas where it forms thick clumps of vegetation and threatens sensitive ecosystems (Queensland Government).
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: 
Reported to respond to fire, (increased flowering). No evidence reported of the species altering the fire regime of an area (Victorian Government).
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: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Kniphofias contain knipholone compounds, making them toxic if eaten. Kniphofias can also cause eye and skin irritation (Kew Science http://www.kew.org/science-conservation/plants-fungi/kniphofia-caulescens-lesotho-red-hot-poker).
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: 
Medium
Answer / Justification: 
Can grow in riparian areas, however only grows to 120 cm and the leaves only have minor serrations. Therefore only has minimal nuisance factor (Victorian Government). In Queensland it has spread into natural areas where it forms thick clumps of vegetation and threatens sensitive ecosystems (Queensland Government). Jepson eFlora lists it as growing to 130 cm (51 inches), but there are no reports of it forming impenetrable thickets.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
Produces seed and spreads by rhizomes (Victorian Government).
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: 
Yes
Points: 
1
Confidence Level: 
Medium
Answer / Justification: 
Produces seed and spreads by rhizomes (Victorian Government).
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: 
In Australia, plants were documented producing viable seed. Gardeners also propagate the plant by seed.
Reference(s): 
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
In Australia, plants were able to produce over 9,000 (estimated) seeds per plant.
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: 
Yes
Points: 
1
Confidence Level: 
High
Answer / Justification: 
In Australia, seed germination of a naturalized population was estimated to be 82%.
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: 
Medium
Answer / Justification: 
Vegetative propagules can flower the first year after they are planted (Dave’s garden). Therefore presumed under natural conditions plants can reach maturity within 1-2 years (Victorian Government).
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: 
In California, K. uvaria blooms from April to July, covering greater than 3 months, and is a prolific seed producer.
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: 
High
Answer / Justification: 
K. uvaria seeds are dispersed by wind and there is not information available on their dispersal by birds or animals.
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: 
Medium
Answer / Justification: 
K. uvaria has small (3 mm long) seeds which are dispersed by wind, however they don’t have any specialised structures to aid this. Therefore it is presumed seeds are capable of dispersing to a distance in the range of 200 m-1 km (Victorian Government).
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: 
No
Points: 
0
Confidence Level: 
Medium
Answer / Justification: 
K. uvaria seeds are dispersed by wind and there is not information available on their dispersal by contaminated seed, equipment, vehicles, boats or clothing.
Reference(s): 
Evaluation Notes
Total PRE Score

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

PRE Score: 
18
Number of questions answered: 
20
Screener Confidence (%): 
72.0
PRE Content Access and Privacy
Evaluation visibility: 
Public - accessible to all site users

Review this Evaluation

2142

Click on the button below to mark this evaluation as "Reviewed". Once you click the button, please wait a second, and the site will return to this Evaluation and your name will be on the "Reviewers List" in the right hand column (below the Evaluation Summary). For more information, please see the help page on How to Review an Evaluation?

Vertical Tabs