Climate Matching Map
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| climatematch-aristea_ecklonii-california-20260110.pdf (1.13 MB) | 1.13 MB |
1. Question 1
Yes
1
Very High
Yes, the native range is from Southern Africa northward and eastward through the country, then sporadically northward to Tanzania and Rwanda (Goldblatt & Manning, POWO, Vincent, L.). The species is reported as naturalized in Australia (Queensland Department), New Zealand (New Zealand Plant Conservation), Great Britain (POWO), Jamaica (Adams, C. D.), India (Sivarajan, V.), Sri Lanka (Wijesundara, S.), the West Himalaya (POWO), and California (Calflora).
Goldblatt, P., and J. Manning. 2020. Cape Plants: A Conspectus of the Cape Flora of South Africa. Pretoria: South African National Biodiversity Institute. pza.sanbi.org.
Vincent, L. 1985. “A Partial Revision of the Genus Aristea (Iridaceae) in South Africa, Swaziland, Lesotho, Transkei and Ciskei”. South African Journal of Botany 51: 209-52. doi:10.1016/S0254-6299(16)31653-4.
Sivarajan, V., and A. Pradeep. 1995. “Aristea Ecklonii Baker (Iridaceae) - A New Record for India”. Rheedea 5: 173-76. doi:10.22244/rheedea.1995.05.02.10.
Adams, C. 1972. Flowering Plants of Jamaica. Mona, Jamaica: University of the West Indies.
Wijesundara, S. 2010. “Invasive Alien Flora of Sri Lanka”. Colombo, Sri Lanka: Ministry of Environment, Sri Lanka.
“New Zealand Plant Conservation Network (NZPCN)”. 2016. New Zealand Plant Conservation Network. http://www.nzpcn.org.nz/.
Council, California Invasive Plant. 2026. “Climate Match Map for Aristea Ecklonii”. https://weedmap.cal-ipc.org/climatematch/?areaType=states&mapView=1%2C-….
Online, Plants. 2026. “Aristea Ecklonii Baker”. https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:435963-1.
Network, New. 2026. “Aristea Ecklonii”. https://www.nzpcn.org.nz/flora/species/aristea-ecklonii/.
Calflora. 2025. “Plant Taxon: Aristea Ecklonii”. https://www.calflora.org/app/taxon?crn=14787.
2. Question 2
Yes
2
High
Yes. Although the vast majority of naturalized locations are not in a climate matched region, the species has naturalized in a modest area of Australia in the Melbourne area, Victoria. This area has a California climate match.
Council, California Invasive Plant. 2026. “Climate Match Map for Aristea Ecklonii”. https://weedmap.cal-ipc.org/climatematch/?areaType=states&mapView=1%2C-….
3. Question 3
Yes
2
Medium
Sri Lanka has listed the species as an Invasive Alien Species (Ranathunga). New Zealand has declared the species a "pest plant" and an "unwanted organism," illegal to breed, sell, distribute, or release anywhere in the country (Healy and McAlpine).
Although not using the language "invasive", Australia has classified the species as a significant environmental weed by various regional authorities in New South Wales (National Herbarium), Victoria (Conn) and Queensland (Batianoff).
Although not using the language "invasive", Australia has classified the species as a significant environmental weed by various regional authorities in New South Wales (National Herbarium), Victoria (Conn) and Queensland (Batianoff).
Healy, A. J, and E Edgar. 1980. Flora of New Zealand. Vol. III. Adventive Cyperaceous, Petalous and Spathaceous Monocotyledons. Vol. 3. Wellington, NZ: Government Printer. https://floraseries.landcareresearch.co.nz/taxa/f1c6ea6e-af34-4ba1-b1e1….
McAlpine, K., and C. Howell. 2024. “List of Environmental Weeds in New Zealand 2024”. Wellington, New Zealand. www.doc.govt.nz.
Wales, National. 2026. “Aristea Ecklonii Baker”. Sydney: Royal Botanic Gardens and Domain Trust. plantnet.rbgsyd.nsw.gov.au.
Batianoff, G., and D. Butler. 2002. “Assessment of Invasive Naturalized Plants in South-East Queensland”. Plant Protection Quarterly. caws.org.au.
Conn, B. 1994. “Iridaceae”. Edited by N. Walsh and T. Entwisle. Melbourne: Inkata Press.
Wijesundara, Ranathunga and S. (2018) 2018. “Alien Invasive Plants in Horton Plains National Park, Sri Lanka: Current Status and Their Management”. Journal of Tropical Botany Conservation Volume 15. https://www.researchgate.net/publication/358313785.
4. Question 4
Yes
3
Medium
Of the three areas of the world where the species appears to be regarded as invasive (New Zealand, Sri Lanka, and southern Australia), only a small portion of southern Australia shares a California climate match. Due to some uncertaintly about Australia's "invasive" declaration (National Herbarium, Conn and Batianoff) I am answering with low confidence.
Batianoff, G., and D. Butler. 2002. “Assessment of Invasive Naturalized Plants in South-East Queensland”. Plant Protection Quarterly 17: 27-34. caws.org.au.
Conn, B. 1994. “Iridaceae”. Edited by N. Walsh and T. Entwisle. Melbourne: Inkata Press.
Wales, National. 2026. “Aristea Ecklonii Baker”. Sydney: Royal Botanic Gardens and Domain Trust. plantnet.rbgsyd.nsw.gov.au.
5. Question 5
No
0
High
No. Although several other Aristea species occur in native African habitats I can find no evidence of wildlands naturalization of the Aristea genus in other areas of the world.
The Iridaceae is a very large famiy and contains several species with invasive tendencies in similar CA climates (Iris pseudacorus, Chasmanthe floribunda, Watsonia meriana, Freesia x hybrida, Romulea rosea, Moraea spp., etc). However, none of these would likely be considered close allies of Aristea.
The Iridaceae is a very large famiy and contains several species with invasive tendencies in similar CA climates (Iris pseudacorus, Chasmanthe floribunda, Watsonia meriana, Freesia x hybrida, Romulea rosea, Moraea spp., etc). However, none of these would likely be considered close allies of Aristea.
No references cited.
6. Question 6
No
0
Very High
No. Of the hundreds of records on the Cal-IPC California Climate Match map very few (--10%) share a California climate match (Cal-IPC).
Council, California Invasive Plant. 2026. “Climate Match Map for Aristea Ecklonii”. https://weedmap.cal-ipc.org/climatematch/?areaType=states&mapView=1%2C-….
7. Question 7
Yes
1
Medium
Yes. In Sri Lanka A. ecklonii is identified as a dominant invasive species that competes with endemic flora, significantly threatening native ecosystems with habitat saturation. A 2018 paper (Ranathunga) says the plant is noted as forming dense, long-lived stands that create an impenetrable ground cover, preventing the germination and establishment of native plant seedlings. Further, it says its spread has reduced the availability of native grasslands. However, this is the only published documentation of displacing native plants I can locate.
Ranathunga, Chandimal, and Siril Wijesundara. 2018. “Alien Invasive Plants in Horton Plains National Park, Sri Lanka: Current Status and Their Management”. Journal of Tropical Botany Conservation.
8. Question 8
No
0
High
Given the small stature, +/- evergreen foliage, limited dry biomass, and more mesic habitat (Zondi, Calflora) it is unlikely to contribute to or substantially alter fire regimes.
Zondi, Sabelo. 2013. “Aristea Ecklonii Baker (Iridaceae)”. PlantZAfrica. South African National Biodiversity Institute.
Calflora. 2025. “Plant Taxon: Aristea Ecklonii”. https://www.calflora.org/app/taxon?crn=14787.
9. Question 9
Yes
1
High
Studies on the antimicrobial properties (in-vitro toxicity) of A. ecklonii have shown that its crude leaf and root extracts exhibit some level of cytotoxicity (Dumisa). However, there is no information correlating this to actual risks to humans/animals.
There is little published evidence of impacts to grazing systems. However the Sri Lanka paper (Ranathunga) does document reduced availability of native grasslands and posing a threat to grazing animals, such as sambar deer.
There is little published evidence of impacts to grazing systems. However the Sri Lanka paper (Ranathunga) does document reduced availability of native grasslands and posing a threat to grazing animals, such as sambar deer.
Dumisa, Mthembeni, Olayinka Aiyegoro, and Sandy van Vuuren. (2026) 2020. “Medicinal Plant: Dye Combinations – Impact on Antimicrobial Potency and Toxicity”. South African Journal of Botany 135. Elsevier: 188-200. doi:10.1016/j.sajb.2020.09.002.
Ranathunga, Chandimal, and Siril Wijesundara. 2018. “Alien Invasive Plants in Horton Plains National Park, Sri Lanka: Current Status and Their Management”. Journal of Tropical Botany Conservation.
10. Question 10
No
0
High
The Sri Lanka paper (Ranathunga) mentions a possible reduction of native grassland, but this would likely not block or slow movement of animals, humans or livestock.
Given the low, herbaceous stature and habit of the plant is not likely to impact modest or larger animals animal, livestock, or human movement. I find no documentation of impacts to smaller arthropods, amphibians, reptiles, herbivores, etc.
Given the low, herbaceous stature and habit of the plant is not likely to impact modest or larger animals animal, livestock, or human movement. I find no documentation of impacts to smaller arthropods, amphibians, reptiles, herbivores, etc.
Ranathunga, Chandimal, and Siril Wijesundara. 2018. “Alien Invasive Plants in Horton Plains National Park, Sri Lanka: Current Status and Their Management”. Journal of Tropical Botany Conservation.
11. Question 11
Yes
1
Very High
Yes. The plant possesses woody rhizomes that enable it to expand locally. These rhizome fragments can be dispersed to new locations by water (floods or stream flow) or by human disturbance activities such as road grading and the movement of soil (Weedbusters). Its rhizomes are highly resilient and if the foliage is killed by fire, grazing, or contact herbicides, the rhizome often survives, could potentially be moved (esp. with soil) and resprout when favorable conditions return (Zondi).
Zondi, Sabelo. 2013. “Aristea Ecklonii Baker (Iridaceae)”. PlantZAfrica. South African National Biodiversity Institute.
2026. “Aristea (Aristea Ecklonii)”. www.weedbusters.org.nz.
12. Question 12
Yes
1
Medium
An invasive plant assessment from Australia (Csurhes, S.) states that seed is the primary method of reproduction, but that it also spreads by rhizomes in water and on road graders, boots and in soil.
Although detached fragments are the primary method of reproduction, seed does appear to nontheless be a "common" method of reproduction (Biosecurity Queensland). Another document makes the same claim (Australian Rainforest).
Although detached fragments are the primary method of reproduction, seed does appear to nontheless be a "common" method of reproduction (Biosecurity Queensland). Another document makes the same claim (Australian Rainforest).
Csurhes, S. 2016. “Invasive Plant Risk Assessment: Blue Stars (Aristea Ecklonii).”
“Weeds of Australia Biosecurity Queensland Edition”. 2011. http://keyserver.lucidcentral.org/weeds/data/03030800-0b07-490a-8d04-06….
Society, Australian. n.d. “Aristea Ecklonii – A Weed Preventing Rainforest Restoration.”
13. Question 13
Yes
1
Very High
Yes, seed is the species primary means of reproduction (Weedbusters, Csurhes, Zondi).
Csurhes, S. 2016. “Invasive Plant Risk Assessment: Blue Stars (Aristea Ecklonii).”
Zondi, Sabelo. 2013. “Aristea Ecklonii Baker (Iridaceae)”. PlantZAfrica. South African National Biodiversity Institute.
2026. “Aristea (Aristea Ecklonii)”. www.weedbusters.org.nz.
14. Question 14
Yes
1
High
The Australian organization Springbrook Rescue states that "One plant could produce more than 5,000 seeds in one fruiting" (Australian Rainforest). Elsewhere, the same paper less specifically states "It produces masses of seed that are spread . . .".
From my own Calflora documentation (Vanderhoff) of mature plants at an Orange County wildland colony my seed estimate was over 1,000 per mature plant. (+/-30 seeds per capsule; +/-12 capsules per flowering stem; +/- 8 flowering stems per season per mature plant = +/-2,880 seeds per year).
It is well documented that abundant seed is its primary method of reproduction.
From my own Calflora documentation (Vanderhoff) of mature plants at an Orange County wildland colony my seed estimate was over 1,000 per mature plant. (+/-30 seeds per capsule; +/-12 capsules per flowering stem; +/- 8 flowering stems per season per mature plant = +/-2,880 seeds per year).
It is well documented that abundant seed is its primary method of reproduction.
Society, Australian. n.d. “Aristea Ecklonii – A Weed Preventing Rainforest Restoration”. Springbrook Rescue. https://springbrookrescue.org.au/AristeaEcklonii.html.
Vanderhoff, Ron. (2026) 2024. “Observation of Aristea Ecklonii.”
15. Question 15
Yes
1
Medium
I can only find anectdotal references to wildland germination success, although they collectively seem supportive of generally good germination.
However, there is a 2019 paper (Colville) of a germination test of an Aristea ecklonii seed lot from the Millenium Seed Bank collected in 2004. Germination was 88%, with seed viability (live seed, capable of germination) at 100%. Of course this was in a controlled environment.
I believe it is reasonable to imply a YES answer to this question, although without specific wildland references, a lower confidence score.
However, there is a 2019 paper (Colville) of a germination test of an Aristea ecklonii seed lot from the Millenium Seed Bank collected in 2004. Germination was 88%, with seed viability (live seed, capable of germination) at 100%. Of course this was in a controlled environment.
I believe it is reasonable to imply a YES answer to this question, although without specific wildland references, a lower confidence score.
Colville, L., and H. Pritchard. 2019. “Assessing Extreme Seed Longevity: The Value of Historic Botanical Collections”. Frontiers in Plant Science 10: 1181. doi:10.3389/fpls.2019.01181.
16. Question 16
Yes
1
High
Although not from scientific publications, the species is documented to flower and seed in either its second or third year from seed. This includes evidence from the Pacific Bulb Society (Pacific Bulb): noting that when growing Aristea ecklonii from seed, you generally must "wait a couple of years" for the first flowers and seed to appear. The same organization states that the first bloom of a plant was in its third year after being obtained as a 4-inch seedling.
Plants of Africa states that "Aristea ecklonii can take 2 to 3 years to reach its ultimate height and maturity" (PlantZAfrica).
Plants of Africa states that "Aristea ecklonii can take 2 to 3 years to reach its ultimate height and maturity" (PlantZAfrica).
Society, Pacific. 2025. “Aristea”. https://www.pacificbulbsociety.org/pbswiki/index.php/aristea.
Network, New. 2026. “Aristea Ecklonii”. https://www.nzpcn.org.nz/flora/species/aristea-ecklonii/.
17. Question 17
Yes
1
Very High
Plant of Africa (Zondi) states a bloom period in wildlands of 6 to 8 months. The Pacific Bulb Society (Pacific Bulb) says in California "it can bloom off and on throughout the year". Although presumably in cultivation, the Random Harvest site (Random Harvest) indicates 8 months of flowering, and Plant Master suggests (Plant Master) 6 months.
All of these provide ample evidence of at least three months of continuous seed production.
All of these provide ample evidence of at least three months of continuous seed production.
2026. “Aristea Ecklonii - Blue Stars”. https://plantmaster.com/plants/eplant.php?plantnum=1719&project=16181.
Zondi, Sabelo. 2013. “Aristea Ecklonii Baker (Iridaceae)”. PlantZAfrica. South African National Biodiversity Institute.
Society, Pacific. 2025. “Aristea”. https://www.pacificbulbsociety.org/pbswiki/index.php/aristea.
Nursery, Random. n.d. “Aristea Ecklonii (Blue Stars, Blousterre, Umhushuza)”. https://www.randomharvest.co.za/South-African-Indigenous-Plants/Show-Pl….
18. Question 18
No
0
High
I can find no research or documentation for this method of dispersal for this species. All documentation refers to vegetative fragment dispersal in water or soil.
The propagules appear to have no nutritional/food incentive to animals and the seed has no barbs or sticky/gelatenous properties, lending to an unlikely transport by an mammal, bird or domestic animal a long distance.
Although minor incidental distribution by mammals, birds or domestic animal is always possible with any propagule it is likely not significant and certainly not "frequent".
The propagules appear to have no nutritional/food incentive to animals and the seed has no barbs or sticky/gelatenous properties, lending to an unlikely transport by an mammal, bird or domestic animal a long distance.
Although minor incidental distribution by mammals, birds or domestic animal is always possible with any propagule it is likely not significant and certainly not "frequent".
No references cited.
19. Question 19
Yes
1
High
Yes. Scientific evidence from Australia and New Zealand confirms that Aristea ecklonii propagules are frequently dispersed long distances, esp. by water.
Water is the primary method for long-distance spread of A. ecklonii especially in riparian and hilly environments (Australian Rainforest). In regions like Springbrook, Queensland, seeds are documented to spread extensively via overland water following rain events (Biosecurity Queensland). In New Zealand, both seeds and rhizome fragments are frequently transported by waterways, enabling colonization far downstream from parent populations (New Zealand Plant Conservation).
Studies on water-dispersal indicate median dispersal distances often range from 20 m to 1.8 km, with extreme events exceeding several kilometers (Soons).
A. ecklonii also produces massive quantities of small, lightweight seeds (Australian Rainforest Conservation)—over 5,000 per fruiting event—which facilitates effective wind dispersal and is a standard mechanism for moving these seeds across open habitats and forest margins.
Water is the primary method for long-distance spread of A. ecklonii especially in riparian and hilly environments (Australian Rainforest). In regions like Springbrook, Queensland, seeds are documented to spread extensively via overland water following rain events (Biosecurity Queensland). In New Zealand, both seeds and rhizome fragments are frequently transported by waterways, enabling colonization far downstream from parent populations (New Zealand Plant Conservation).
Studies on water-dispersal indicate median dispersal distances often range from 20 m to 1.8 km, with extreme events exceeding several kilometers (Soons).
A. ecklonii also produces massive quantities of small, lightweight seeds (Australian Rainforest Conservation)—over 5,000 per fruiting event—which facilitates effective wind dispersal and is a standard mechanism for moving these seeds across open habitats and forest margins.
Soons, M., M. Teiller, N. Peerlings, R. van Diggelen, and W. Ozinga. 2017. “Seed Size Regulates Plant Dispersal Distances in Flowing Water”. Journal of Ecology 105: 1037-49. doi:10.1111/1365-2745.12745.
Queensland, Biosecurity. 2008. “Invasive Plant Risk Assessment: Blue Stars (Aristea Ecklonii).”
Society, Australian. n.d. “Aristea Ecklonii – A Weed Preventing Rainforest Restoration”. Springbrook Rescue. https://springbrookrescue.org.au/AristeaEcklonii.html.
Network, New Zealand Plant Conservation. 2026. “Aristea Ecklonii”. https://www.nzpcn.org.nz/flora/species/aristea-ecklonii/.
20. Question 20
Yes
1
Very High
Yes. Scientific and environmental management records in Australia and New Zealand confirm that Aristea ecklonii is frequently dispersed in these ways.
Seeds are commonly transported long distances on the boots of hikers and walkers and contaminated soil adhering to footwear (Australian Rainforest). The same source and the Auckland Council (Tiaki) says propagules are frequently spread by machinery, road graders. and road maintenance activities along road corridors. Boats are also likely to transport propagules, but I was unable to document this. The species is documented as frequently spread in contaminated soil moved during landscaping or development projects (Australian Rainforest, Tiaki, Biosecurity Queensland).
The horticultural trade is discussed as the most significant pathway for A. ecklonii introduction and spread (Australian Rainforest, Biosecurity Queensland). In California A. ecklonii is moderately sold by nurseries as a garden plant.
Seeds are commonly transported long distances on the boots of hikers and walkers and contaminated soil adhering to footwear (Australian Rainforest). The same source and the Auckland Council (Tiaki) says propagules are frequently spread by machinery, road graders. and road maintenance activities along road corridors. Boats are also likely to transport propagules, but I was unable to document this. The species is documented as frequently spread in contaminated soil moved during landscaping or development projects (Australian Rainforest, Tiaki, Biosecurity Queensland).
The horticultural trade is discussed as the most significant pathway for A. ecklonii introduction and spread (Australian Rainforest, Biosecurity Queensland). In California A. ecklonii is moderately sold by nurseries as a garden plant.
Council, Tiaki. 2026. “Pest Search: Aristea”. https://www.tiakitamakimakaurau.nz/protect-and-restore-our-environment/….
Society, Australian. n.d. “Aristea Ecklonii – A Weed Preventing Rainforest Restoration”. Springbrook Rescue. https://springbrookrescue.org.au/AristeaEcklonii.html.
Queensland, Biosecurity. 2008. “Invasive Plant Risk Assessment: Blue Stars (Aristea Ecklonii)”. Brisbane, Australia. www.publications.qld.gov.au.
Evaluation Notes
This evaluation was helped by a reasonably high amount of published research, also leading to higher confidence.
Total PRE Score
19
20
81
