Fountain grass (Cenchrus setaceus)

Assessment ID: 4595
Jurisdiction: North Territory
Methodology: Northern Territory Weed Risk Management System - terrestrial
Management area: Tennant Creek Region

Notes: Technical report available at https://environment.nt.gov.au/__data/assets/pdf_file/0020/258014/wra-report-fountain-grass-updated-logo.pdf.

Status: PUBLISHED
Last updated: 21/8/2025 3:00:52 pm AEST

Questions answered: 39 / 47

Weed Risk: 352.62 (Very high)
   Invasiveness (raw/adjusted): 9.00 / 7.497
   Impacts (raw/adjusted): 10.00 / 5.260
   Potential distribution (raw/adjusted): 17.00 / 8.942

Feasibility of Control: 293.59 (High)
   Control costs (raw/adjusted): 6.00 / 5.454
   Current distribution (raw/adjusted): 10.00 / 10.000
   Persistence (raw/adjusted): 7.00 / 5.383

Result: Prevent entry, contain regional spread, protect priority sites

Invasiveness

A1. What is the ability of the plant to establish amongst intact native environments?
Answer: High

Comments: 
Fountain grass is an aggressive invader in the arid and semi-arid habitats of the tropics and subtropics (Gonzalez-Rodriguez et al. 2010).

Fountain grass is apparently able to take advantage of rainfall with higher photosynthetic rates whenever there is enough precipitation (Poulin et al. 2007).

This species is known to occur in deserts, grasslands and disturbed sites such as roadsides (European and Mediterranean Plant Protection Organization 2010).

It can grow on all types of soils (clay to sandy), acid to slightly alkaline, but does not tolerate saline conditions (European and Mediterranean Plant Protection Organization 2010).
 
It requires full sun for the survival and development but tolerates partial shade (Floridata 2010).

Fountain grass is extremely drought tolerant. Established plants thrive in climates with less than 20 inches (500 mm) of rain annually (Floridata 2010).

It is a weed of woodlands, grasslands, coastal vegetation, rail embankments, roadsides and mines (FloraBase 2010).

Seedlings readily establish in wetter years and then become drought tolerant in drier years, allowing it to maintain dominance over other grasses (FloraBase 2010).

It has phenotypic plasticity (Poulin et al. 2007).
 
It can invade riparian habitats, flood lines and rocky shores of reservoirs and rivers in low elevation (Arizona-Sonora Desert Museum 2010).

This plant is considered mildly invasive if planted near undisturbed natural areas (Horticopia Inc. 1999 cited in Pacific Island Ecosystems at Risk 2005, Horticopia Inc. 1999, Pacific Island Ecosystems at Risk 2005).
 
More references available at https://environment.nt.gov.au/__data/assets/pdf_file/0020/258014/wra-report-fountain-grass-updated-logo.pdf.

A2. What is the reproductive ability of the plant?

(a) Time to seeding
Answer: 1 year or less

Comments: 
Plant reaches maturity in the first year, and produces seeds every year (European and Mediterranean Plant Protection Organization 2010).

(b) Annual production of viable seed /m2 or /plant
Answer: Low

Comments: 
An average of 100 seeds per plant was measured in a greenhouse trial (Poulin et al. 2007).

Produces large amounts of seed (Herbiguide 2010).

Seed set is usually quite low, typically less than 20% = less than 50 seeds per seed head; Total (viable?) seed production recorded as <1000/m2 (Pacific Island Ecosystems at Risk 2005).

(c) Vegetative reproduction
Answer: None

Comments: 
No evidence of vegetative reproduction.

A3. Do propagules of the plant have properties that allow them to be dispersed long-distance by natural means?

(a) Flying animals (birds, bats)
Answer: Do not know

Comments: 

(b) Other wild animals
Answer: Yes

Comments: 
Seeds may be spread by animals (Poulin et al. 2007).

(c) Water
Answer: Yes

Comments: 
Seeds may be dispersed by water (Benton 2005).

(d) Wind
Answer: Yes

Comments: 
Fountain grass seeds are primarily wind-dispersed (Benton 2005, Poulin et al. 2007).

A4. How likely is long-distance dispersal by human-assisted means?

(a) Deliberate spread by people
Answer: Occasional

Comments: 
Fountain grass has been widely planted as an ornamental in Australia and overseas. However, like many other “garden escapees”, it is highly invasive, fire-adapted colonizer that readily out-competes native plants (DPI Queensland 2008).

Fountain grass is a declared weed in Qld and NSW, but it is still sold as a garden plant in other states (CRC for Australian Weed Management 2008).

(b) Accidentally by people and vehicles
Answer: Occasional

Comments: 
Scattered populations occur in windward areas, mostly in roadside habitats. Fountain grass is readily dispersed by vehicles, humans, wind, water, and possibly birds (Tunison 1992).

Seeds caught in the base of the plant, can spread after the plant is uprooted (Global Invasive Species Database 2010).

(c) Contaminated produce
Answer: Unlikely

Comments: 

(d) Domestic/farm animals
Answer: Occasional

Comments: 
Seeds may be dispersed by livestock (Benton 2005).

Impacts

B1. What is the plant's competitive potential?
Answer: High

Comments: 
In dry and open environments fountain grass is a highly aggressive, fire-adapted colonizer that readily out-competes native plants (Poulin et al. 2007).

Fountain grass out-competes and suppresses native vegetation, invades pasture, spread rapidly along roadsides, railways and fence lines, and greatly increases fire risk (Eyre Peninsula Natural Resources Management Board 2010).
 
Seeds can remain viable in the soil for 6 years or longer (European and Mediterranean Plant Protection Organization 2010).
 
Fountain grass is of low grazing values because of its coarse rough leaves (DPI NSW 2010).

It is a highly invasive plant forming monoculture and out-competing native plants by reducing available resources such as space, water and nutrients (European and Mediterranean Plant Protection Organization 2010).

It can produce seeds apomitically (asexually) (Global Invasive Species Database 2010, Poulin et al. 2007).

This study conducted in the Canary Islands reported that fountain grass has high phenotype plasticity, and has been able to readily adapt to the low levels of resources available in the study area (Gonzalez-Rodriguez et al. 2010).

This study reported that the activity of photosystem II was higher and lasted longer in P. setaceum than in the native grasses (Gonzalez-Rodriguez et al. 2010).
 
(In the Canary Islands) Cenchrus setaceus first coexists with, and eventually replaces, the native grasses Hyparrhenia hirta, Cenchrus ciliaris, and Aristida adscensionis ssp. coerulescens as urban areas enlarge (Gonzalez-Rodriguez et al. 2010, Martín Esquivel et al. 1995).

B2. What is the plant’s potential to modify the existing fire behaviour and alter the fire regime?
Answer: Significant potential

Comments: 
In the Hawaiian Islands, C. setaceus is an extremely noxious weed because it is an early aggressive colonizer of lava fields and dry forests on the Islands of Hawaii, and this has led to the destruction of native communities by increasing fire frequency and by limiting germination, survival, and growth of native dry forest species (Poulin et al. 2007).

Fountain grass produces lots of fuel loads, which increases the intensity and spread of a fire in dry forests (Benton 2005).

B3. What is the plant’s potential to restrict the physical movement of people, animals, vehicles, machinery and/or water?
Answer: None

Comments: 

B4. What is the plant’s potential to negatively affect the health of animals and/or people?
Answer: None

Comments: 
Not recorded as toxic.

B5. Does the plant potentially have negative effects on natural and cultural values?

(a) Reducing habitat quality for native animals?
Answer: High

Comments: 
In the Hawaiian Islands, C. setaceus is an extremely noxious weed because it is an early aggressive colonizer of lava fields and dry forests on the Islands of Hawaii, and this has led to the destruction of native communities by increasing fire frequency and by limiting germination, survival, and growth of native dry forest species (Poulin et al. 2007).
 
It is a highly invasive plant forming monoculture and out-competing native plants by reducing available resources such as space, water and nutrients (European and Mediterranean Plant Protection Organization 2010).

(b) Threatened species or communities
Answer: More than one

Comments: 
There are two species of threatened land snail with highly restricted distributions close to Alice Springs, Semotrachia filixiana and Semotrachia euzyga. These species and others would be impacted by fountain grass if it were to escape and spread (D. Liddle, NT Biodiversity Conservation, pers. comm. 2010, Ward et al. 2006, Wilson et al. 2007).

(c) Sites of natural or cultural significance
Answer: More than one

Comments: 
The Greater MacDonnell Ranges is a site of conservation significance that may be impacted by Cenchrus setaceus (D. Liddle, NT Biodiversity Conservation, pers. comm. 2010, Harrison et al. 2009).
 
The Waterhouse Range is a site of conservation significance that may be impacted by Cenchrus setaceus (D. Liddle, NT Biodiversity Conservation, pers. comm. 2010) (Harrison et al. 2009).

B6. Is the plant presumed to have negative effects on environmental health?

(a) Soil chemistry/stability
Answer: No

Comments: 
Used for binding sand to prevent erosion (Herbiguide 2010).

(b) Water quality
Answer: No

Comments: 
Terrestrial species.

(c) Hydrology
Answer: No

Comments: 

Potential distribution

C1b. What is the Climatch suitability score (which indicates the proportion of the NT environment that is suitable for the plant)?
Answer: 10

Comments: 
The CLIMATCH model used by the NT Weed Management Branch predicts that 95% of the Northern Territory is climatically suitable for Cenchrus setaceus (see Figure 1) (NT Weed Management Branch 2010).
 
This species is known to occur in deserts, grasslands and disturbed sites such as roadsides (European and Mediterranean Plant Protection Organization 2010).

C2. How many broad habitat types in the NT will the plant potentially naturalise in (up to 5)?
Answer: Five or more

Comments: 
The broad vegetation types in the Northern Territory that Pennisetum setaceum will potentially naturalise in are: 
  - Tropical riparian areas 
   - Tropical open forests/savanna woodlands 
   - Sandstone heathlands 
   - Mitchell grasslands 
   - Spinifex grasslands 
   - Arid and semi-arid woodlands 
   - Arid and semi-arid shrublands 
   - Arid riparian 
 Of these, the favoured vegetation type is arid riparian (NT Weed Risk Management Committee 2010, Rossiter-Rachor et al. 2012).

C3. What is the potential of the plant to occur throughout its favoured habitat in the NT (as identified in question 2)?
Answer: Some

Comments: 
Cenchrus setaceus has the potential to occur through some of its favoured habitat (NT Weed Risk Management Committee 2010).

Control costs

A1. How detectable is the weed?

(a) Distinguishing features
Answer: Sometimes distinct

Comments: 
Fountain grass is an attractive perennial grass with a densely clumped growth form and erect stems that grow 1 m high (Benton 2005).

Fountain grass is a tufted perennial grass to 1.5 m high (DPI NSW 2010).

The leaves coloration may depend on water availability; they are green in winter and brown in summer (European and Mediterranean Plant Protection Organization 2010).

The small flowers are grouped in pink or purple colour, long feathery inflorescences up to 8-30 cm long (European and Mediterranean Plant Protection Organization 2010).

(b) Active growth period
Answer: <4 months

Comments: 
It is a perennial species (Germplasm Resources Information Network 2010).

Seeds germinate autumn to winter and grow slowly until spring. The main growth occurs over summer and it is semi-dormant in winter (Herbiguide 2010).
 
Fountain grass flowers mainly in spring, however is recorded from July to November and occasionally in March (Herbiguide 2010).

(c) Height at maturity
Answer: 0.5 - 2 m

Comments: 
It can grow up to 1.5 m high (DPI NSW 2010).

A2. What is the general accessibility of infestations at the optimum treatment time?
Answer: High

Comments: 
It is believed that in the NT, fountain grass is restricted to inhabited areas of Alice Springs township with good access (NT Weed Management Branch 2010).

A3. How expensive is control of the weed in the first year of targeted control, for an infestation that has reached maximum weed density?

(a) Chemical costs
Answer: Low

Comments: 
Chemical cost for control of this species is low. Glyphosate would be sufficient to treat an infestation (D. Christen & M. Fuller, pers. comm. 2010).

(b) Labour cost
Answer: Low

Comments: 
Current infestation have good access (D. Christen & M. Fuller, pers. comm. 2010).

(c) Equipment cost
Answer: Low

Comments: 
Spraypack would be sufficient equipment (D. Christen & M. Fuller, pers. comm. 2010).

A4. What is the general community perception of this weed within the region?
Answer: Low

Comments: 

Current distribution

B1. What is the current pattern of the species’ distribution across the weed management region?
Answer: Restricted

Comments: 
It has naturalised over a wide range from Western Australia to the south-eastern corner of South Australia, northern Queensland, the greater Brisbane area and most of New South Wales (Csurhes & Edwards 1998, Hnatiuk 1990).

[Note: marked as absent from Tennant Creek Region].

Persistence

C1. How long will it take to reach the maintenance period?
Answer: Low

Comments: 
Seeds can remain viable in the soil for six years or longer (Benton 2005).

C2. What is the minimum time period for reproduction of sexual or vegetative propagules?
Answer: <1 years

Comments: 
Plant reaches maturity in the first year, and produces seeds every year (European and Mediterranean Plant Protection Organization 2010).
 
It is a fast growing species and can live to up to 20 years (Global Invasive Species Database 2010).

C3. What is the maximum longevity of sexual or vegetative propagules?
Answer: >5 years

Comments: 
Seeds can remain viable in the soil for six years or longer (Benton 2005).
 
Mature plants can live to up to 20 years (Global Invasive Species Database 2010).

C4. What is the threat of reinfestation from outside the management region?

(a) Long-distance (>100m) dispersal by natural means
Answer: Rare

Comments: 
Seeds may be spread by animals (Poulin et al. 2007).

Seeds may be dispersed by water (Benton 2005).

Fountain grass seeds are primarily wind-dispersed (Benton 2005).

(b) Long-distance (>100m) dispersal by human means
Answer: Rare

Comments: 
African fountain grass has been widely planted as an ornamental in Australia and overseas (DPI Queensland 2008).

Scattered populations occur in windward areas, mostly in roadside habitats. Fountain grass is readily dispersed by vehicles, humans, wind, water, and possibly birds (Tunison 1992).

Seeds may be dispersed by livestock (Benton 2005).

It is cultivated as an ornamental for its graceful, arching habit and occasionally escapes cultivation (Harden 1993 cited in Csurhes & Edwards 1998, Harden 1993).

References

Arizona-Sonora Desert Museum (2010). Invaders: Fountain grass (Pennisetum setaceum). http://www.desertmuseum.org/invaders/invaders_fountaingrass.php. Accessed 29/04/2010. Baker, H. G. (1965). Characteristics and modes of origin of weeds. In: The genetics of colonizing species (eds. H. G. Baker and G. L. Stebbins), pp. 147-168. Academic Press, New York, New York, USA. Benton, N. (2005). Fact Sheet: Fountain grass. http://www.nps.gov/plants/alien/fact/pese1.htm. Accessed 06/05/2010. Cooperative Research Centre for Australian Weed Management (2008). Weed Management Guide -feathergrasses and mission grasses (Pennisetum species). CRC for Australian Weed Management. Csurhes and Edwards (1998). Potential environmental weeds in Australia. Environment Australia, Canberra. Department of Primary Industries NSW (2010). Weed Alert: Fountain grass (Pennisetum setaceum). www.dpi.nsw.gov.au/weeds. Accessed 29/04/2010. Department of Primary Industries Queensland (2008). Fact sheet: African fountain grass (Pennisetum setaceum). http://www.dpi.qld.gov.au/documents/Biosecurity_EnvironmentalPests/IPA-African-FountainGrass-PP146.pdf. Accessed 29/04/2010. European and Mediterranean Plant Protection Organization (2010). Pennisetum setaceum (Poaceae). European and Mediterranean Plant Protection Organization, http://www.eppo.org/QUARANTINE/Alert_List/invasive_plants/Pennisetum_setaceum.htm. Accessed 29/04/2010. More references available at https://environment.nt.gov.au/__data/assets/pdf_file/0020/258014/wra-report-fountain-grass-updated-logo.pdf.