Pennisetum ciliare Risk – California Invasive Plant Council

Created by: Chris McDonald
Created on: Tuesday, Sep 20th, 2022

Evaluation Summary

Buffelgrass is a perennial grass that has been introduced as a forage species and for erosion control in semi-tropical to semi-arid regions across the globe. It was introduced to North America to increase forage production in semi-arid habitats and has expanded into natural areas. It has many characteristics that allow it to become invasive and spread, including asexual seed production, easily dispersed seeds, high seed production and tolerance of drought. Buffelgrass is invasive in the southwestern US and Mexico, and so far only a few populations have been found or have established in California.

General Evaluation Information

Date of Evaluation:

September 20, 2022

Evaluation Time (hrs):

Not Recorded

Evaluation Status:

Completed

Plant Information

Plant:

Pennisetum ciliare

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
Buffelgrass climate matching map.pdf	1.08 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:

Buffelgrass has invaded southwestern North America, Arizona, New Mexico, Texas, Mexico incl. Sonora and Chihuahua. Also invading in Australia and South Central Asia (India, Pakistan), and also found in Hawaii. Native to Africa and the Middle East. Buffelgrass is on the Arizona noxious weed list and the New Mexico watch list.

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

Olsson, A. D., Betancourt J. L., Crimmins M. A., & Marsh S. E. (2012). Constancy of local spread rates for buffelgrass (Pennisetum ciliare L.) in the Arizona Upland of the Sonoran Desert. Journal of Arid Environments. 87, 136–143.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

Lucid Central (2016). Weeds of Australia: Buffelgrass.

Arizona department of Agriculture (2022). Arizona Noxious Weed List.

Beck, L., & Wanstall J. (2020). New Mexico Noxious Weed List.

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:

Buffelgrass is invasive in Australia and southwestern North America, where the climate is similar to California including the Sonoran Desert.

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

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:

Very High

Answer / Justification:

Invasive in US and Australia

Reference(s):

Farrell, H. L., & Gornish E. S. (2019). Pennisetum ciliare: a review of treatment efficacy, competitive traits, and restoration opportunities. Invasive Plant Science and Management. 12, 203–213.

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

Lucid Central (2016). Weeds of Australia: Buffelgrass.

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:

Very High

Answer / Justification:

Invading southwestern North America and Australia, both of which have climates that match California.

Reference(s):

Farrell, H. L., & Gornish E. S. (2019). Pennisetum ciliare: a review of treatment efficacy, competitive traits, and restoration opportunities. Invasive Plant Science and Management. 12, 203–213.

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

GBIF—the Global Biodiversity Information Facility (2021). GBIF Distribution Map Buffelgrass Pennisetum ciliare, Cenchrus ciliaris.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

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:

Several other Pennisetum's are also invasive. Including Fountaingrass (Pennisetum setaceum), kikuyu (Pennisetum clandestinum) Chinese fountain grass (P. alopecuroides) . Buffelgrass is also listed as Cenchrus ciliaris, several other Cenchrus' are also invasive (Cenchrus setiger)

Reference(s):

DiTomaso, J. M., & Healy E. A. (2013). Weed control in natural areas in the Western United States. 544.

Mastalerz, A., & Frey M. (2012). Invasive Plant Alert: Fountain Grass Pennisetum alopecuroides (L.) Spreng..

USDA NRCS (2017). USDA PLANTS Database: Pennisetum alopecuroides (Chinese fountaingrass).

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

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Buffelgrass grows in southern Africa, the middle east, south central Asia, eastern Australia, southwestern North America and all these places match the climate of California. Buffelgrass seems to occur in about half of climate zones that it grows in that also match California. (NOTE: not listed as very high confidence, because there are several large semi-tropical areas where buffelgrass grows that are outside climate of CA, eastern Africa, eastern South America (Brazil), Texas and central Mexico.)

Reference(s):

GBIF—the Global Biodiversity Information Facility (2021). GBIF Distribution Map Buffelgrass Pennisetum ciliare, Cenchrus ciliaris.

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:

Buffelgrass displaces native plants in several locations where it is invasive, including Australia, Hawaii, and Sonoran Desert. It can also overtop and smother smaller native plants.

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

Jackson, J. (2005). Is there a relationship between herbaceous species richness and buffel grass (Cenchrus ciliaris)?. Austral Ecology. 30, 505–517.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

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

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

Buffel grass adds fuels to desert ecosystems where fuels are historically limited. Buffelgrass also adds fuels to semi-tropical grassland ecosystems altering the fire regime.

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

McDonald, C. J., & McPherson G. R. (2013). Creating hotter fires in the Sonoran Desert: Buffelgrass produces copious fuels and high fire temperatures. Fire Ecology. 9, 26–39.

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:

Very High

Answer / Justification:

Buffelgrass is often introduced to semi-arid ecosystems to increase forage for livestock. Buffelgrass has been viewed as a beneficial forage grass for livestock producers.

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

C Hanselka, W. (1988). Buffelgrass—South Texas wonder grass.

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

Yes or No:

Points:

Confidence Level:

Very High

Answer / Justification:

While buffelgrass increases fuels and has been planted as a forage grass, it does not create impenetrable thickets for most animal species. The grass is generally less than 1.5 m tall and less than 1 m tall when not in flower. It does alter habitat quality and decrease species richness.

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

Reproductive Strategies

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

Yes or No:

Yes

Points:

Confidence Level:

High

Answer / Justification:

Buffelgrass can reproduce via stolons or rhizomes. The main mode of reproduction is by seed and is apomictic (produces seed asexually).

Reference(s):

Bashaw, EC., & Hignight KW. (1990). Gene transfer in apomictic buffelgrass through fertilization of an unreduced egg. Crop Science. 30, 571–575.

Cook, B. (2007). Buffel grass fact sheet.

Tu, M., Randall J., Rice B., Tillery K., Harris M., & Connor L. (2014). BugwoodWiki: Pennisetum ciliare.

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:

High

Answer / Justification:

Buffelgrass is a grass and may occasionally reproduce by tillers separating from the parent plant, however this is uncommon and would require the plant to be disturbed.

Reference(s):

USDA Forest Service (2014). Field Guide for Managing Buffelgrass in the Southwest.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

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

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

Yes, reproduces by seed

Reference(s):

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

Bashaw, EC., & Hignight KW. (1990). Gene transfer in apomictic buffelgrass through fertilization of an unreduced egg. Crop Science. 30, 571–575.

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

Yes or No:

Yes

Points:

Confidence Level:

Very High

Answer / Justification:

Individual buffelgrass inflorescences can produce over one hundred seeds and individual plants can have dozens of inflorescences.

Reference(s):

Kumar, D., Dwivedi GK., & Singh SN. (2005). Seed yield and quality of buffel grass (Cenchrus ciliaris) as influenced by row spacing and fertilizer level. Tropical grasslands. 39, 107–111.

Arizona Sonora Desert Museum (2022). Save Our Saguaros: Beat Back Buffelgrass.

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:

Confidence Level:

Very High

Answer / Justification:

Germination of buffelgrass seeds was 25-35% in India and similarly as high in Mexico when placed under warm growing conditions. Seed viability drops over time.

Reference(s):

Kumar, D., Dwivedi GK., & Singh SN. (2005). Seed yield and quality of buffel grass (Cenchrus ciliaris) as influenced by row spacing and fertilizer level. Tropical grasslands. 39, 107–111.

Hacker, JB., & Ratcliff D. (1989). Seed dormancy and factors controlling dormancy breakdown in buffel grass accession from contrasting provenances. Journal of Applied Ecology. 201–212.

Villa-Reyes, F., & de la Barrera E. (2016). Environmental cues for germination of the invasive bunch grass Pennisetum ciliare (L.) Link. Acta Physiologiae Plantarum. 38, 1–8.

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:

Very High

Answer / Justification:

Buffelgrass plants can produce seed in two years or less.

Reference(s):

Kumar, D., Dwivedi GK., & Singh SN. (2005). Seed yield and quality of buffel grass (Cenchrus ciliaris) as influenced by row spacing and fertilizer level. Tropical grasslands. 39, 107–111.

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

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:

Buffelgrass is a C4 grass and generally reproduces during the warm summer rains. It can produce flowers from spring through summer or anytime the soil is wet and warm enough. Jepson lists flowering from April to October.

Reference(s):

Arizona Sonora Desert Museum (2022). Save Our Saguaros: Beat Back Buffelgrass.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

Smith, Jr., J. P. (2012). Jepson eFlora: Buffelgrass.

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:

Very High

Answer / Justification:

Buffelgrass seeds can disperse via animals, including getting stuck in their fur, and buffelgrass seeds can spread long distances and new patches form long distances from previously known patches.

Reference(s):

USDA Forest Service (2014). Field Guide for Managing Buffelgrass in the Southwest.

Arizona Sonora Desert Museum (2022). Save Our Saguaros: Beat Back Buffelgrass.

Tu, M., Randall J., Rice B., Tillery K., Harris M., & Connor L. (2014). BugwoodWiki: Pennisetum ciliare.

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

Yes or No:

Yes

Points:

Confidence Level:

Medium

Answer / Justification:

Seeds have bristles and can be spread by wind or water. Several sources suggest seeds can float. And populations can spread and disperse quickly in variety of patterns (guerrilla and phalanx, see Olssen et al. 2012).

Reference(s):

USDA Forest Service (2014). Field Guide for Managing Buffelgrass in the Southwest.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

Lucid Central (2016). Weeds of Australia: Buffelgrass.

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

Yes or No:

Points:

Confidence Level:

Low

Answer / Justification:

Seed dispersal can be on clothes as the seeds have bristles, however references do not suggest the frequency of this type of dispersal. Most often buffelgrass is intentionally dispersed to increase forage, or seeds are dispersed by wind, water or animals. Buffelgrass has been introduced across the globe intentionally as a pasture grass, to remediate reduced forages, while others have viewed its invasiveness as a problem for natural areas (see Marshall et al. 2012).

Reference(s):

USDA Forest Service (2014). Field Guide for Managing Buffelgrass in the Southwest.

CABI, Invasive Species Compendium (2014). Invasive Species Compendium: Buffelgrass.

Arizona Sonora Desert Museum (2022). Save Our Saguaros: Beat Back Buffelgrass.

Marshall, VM., Lewis MM., & Ostendorf B. (2012). Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review. Journal of Arid Environments. 78, 1–12.

Evaluation Notes

Websites accessed:

Pennisetum ciliare (L.) Link in GBIF Secretariat (2021). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omeiaccessed via GBIF.org on 2022-11-30.

https://keyserver.lucidcentral.org/weeds/data/media/Html/cenchrus_ciliaris.htm accessed 2022-11-30.

https://agriculture.az.gov/pestspest-control/agriculture-pests/noxious-weeds accessed 2022-11-30

https://wiki.bugwood.org/Pennisetum_ciliare#Reproduction accessed 2022-11-30

https://pubs.nmsu.edu/_circulars/CR698/ accessed 2022-11-30

https://www.desertmuseum.org/buffelgrass/learn.php access 2022-11-30

James P. Smith, Jr. 2012, Pennisetum ciliare, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=36817, accessed on November 30, 2022.

https://keys.lucidcentral.org/keys/v3/pastures/Html/Buffel_grass.htm accessed 2022-11-30

Total PRE Score

< 13 : Low Potential Risk
13 - 15 : Moderate Potential Risk
> 15 : High Potential Risk

PRE Score:

Number of questions answered:

Screener Confidence (%):

90.0

PRE Content Access and Privacy

Organization:

2022 Western PM Grant Project

California Invasive Plant Council (Cal-IPC)

PlantRight

University of California Agriculture and Natural Resources

Evaluation visibility:

Public - accessible to all site users

Nicole Valentine	December 15, 2022
Lauren Quon	December 14, 2022
Scott Oneto	December 14, 2022
Michael Chamberland	October 24, 2022
Jutta Burger	October 23, 2022
Marie Jasieniuk	October 19, 2022

California Invasive Plant Council

Protecting California’s environment and economy from invasive plants

Pennisetum ciliare Risk Assessment

Pennisetum ciliare -- California

Primary tabs

Websites accessed:

Pennisetum ciliare (L.) Link in GBIF Secretariat (2021). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omeiaccessed via GBIF.org on 2022-11-30.

https://keyserver.lucidcentral.org/weeds/data/media/Html/cenchrus_ciliaris.htm accessed 2022-11-30.

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