Monto Vetiver Grass (Vetiveria zizanioides)

Present distribution

Scientific name:	Vetiveria zizanioides (L.) 'Monto'
Common name(s):	Monto vetiver grass

This weed is not known to be naturalised in Victoria

Habitat:

A C4 grass from southern India, Monto vetiver grass is tolerant of a wide range of climatic conditions and soil types; thriving under a Mediterranean climate. It has not, however, been reported outside of cultivation (Truong 2000). There is no evidence that Monto vetiver has established beyond planted populations anywhere in the world. Without any evidence of naturalised populations, a CLIMATE analysis of this cultivar cannot be performed. In addition to this the climate modelling of the parent species, Vetiveria zizanioides, indicated that the species has a tropical to subtropical potential distribution and is unlikely to occur in Victoria, despite reports that it has naturalised in a number of other countries.

Potential distribution

Potential distribution of the parent species, Vetiver zizanioides, produced from CLIMATE modelling

Map Overlays Used

Land Use:

Broad vegetation types

Colours indicate possibility of Vetiver zizanioides infesting these areas.

In the non-coloured areas the plant is unlikely to establish as the climate, soil or landuse is not presently suitable.

Important note for this assessment
The results of this assessment (including the invasiveness, impacts and distribution) can only be applied to the sterile Monto vetiver strain, and, if planting Monto vetiver, it must be propagated vegetatively from known Monto sources, and NEVER propagated by seed. Fertile varieties should not be planted as they may produce seed and are potentially invasive. Only sterile cultivars such as “Monto” should be planted.

map showing the potential distribution of monto vetiver grass

Red= Very high	Orange = Medium
Yellow = High	Green = Likely

Impact

QUESTION	COMMENTS	RATING	CONFIDENCE
Social
1. Restrict human access?	A Dense hedge forming grass that can grow to 3m tall and can have many small barbs which can cut skin, however can be cut back so only impedes access (National Research Council 1993).	mh	mh
2. Reduce tourism?	In most cases planted as a hedging plant in an agricultural setting, if escapes into wetlands could alter shallow wetlands into dense grass, altering the aesthetics and restricting access such as fishing.	ml	mh
3. Injurious to people?	Possesses many small barbs that can cut skin (National Research Council 1993).	mh	mh
4. Damage to cultural sites?	Is a large grass species and may form visual barrier, is also a deep rooted species although no structural damage reported, can alter the topography of a slope when planted as a hedge it restricts soil movement that it builds up to from terraces (National Research Council 1993).	m	mh
Abiotic
5. Impact flow?	Used as a semi permeable barrier to reduce erosion of cultivated slopes, in this case it slows the water flow so that particulates drop out of suspension (National Research Council 1993), little data on impact in its native wetlands however it is an attached emergent and would slow water flow.	h	mh
6. Impact water quality?	little data on impact in its native wetlands however is reported to slow water flow, and as a 3m tall dense grass would lower light levels.	ml	l
7. Increase soil erosion?	Used to reduce soil erosion, erosion only reported to occur when roots harvested for oil (National Research Council 1993).	l	mh
8. Reduce biomass?	Is a tall and densely growing grass species most probably an increase in biomass.	l	m
9. Change fire regime?	Has been reported to stop fire spread when planted adjacent to a cane field, which is being burnt, however naturally grows in wetlands which don’t regularly burn (National Research Council 1993).	l	mh
Community Habitat
10. Impact on composition (a) high value EVC	Not known in Temperate climates, CLIMATE match unlikely. May grow within Victoria unlikely to naturalise.	l	m
(b) medium value EVC	Semi-Aquatic species. All Victorian water bodies considered to comprise high value EVCs only (Weiss pers. coms.) .	l	h
(c) low value EVC	Semi-Aquatic species. All Victorian water bodies considered to comprise high value EVCs only (Weiss pers. coms.) .	l	h
11. Impact on structure?	Can restrict the growth of other cultivation weeds, as rhizomes can’t penetrate its root system, also reported to reduce areas of open water in wetlands reducing submerged and floating vegetation (Greenfield 1989).	h	mh
12. Effect on threatened flora?	No specific data however in native wetlands when grazing was stopped and its growth no longer impeded, it with Paspalum distichum did dominate all other species (Greenfield 1989).	mh	m
Fauna
13. Effect on threatened fauna?	No specific data however in native wetlands when grazing was stopped and its growth no longer impeded. It with Paspalum distichum did reduce areas of open water reducing habitat and food sources for water birds and fish (Greenfield 1989).	mh	m
14. Effect on non-threatened fauna?	In native wetlands when grazing was stopped and its growth no longer impeded it did with Paspalum distichum reduce areas of open water reducing habitat and food sources for water birds and fish (Greenfield 1989).	h	mh
15. Benefits fauna?	Is reported to be not very palatable and due to its dense nature and barbs on leaves doesn’t provide habitat to species (National Research Council 1993).	mh	mh
16. Injurious to fauna?	Barbs on leaves can cut skin, and there is a belief in India that the plant restricts the movements of snakes as the barbs cut them (National Research Council 1993).	mh	mh
Pest Animal
17. Food source to pests?	New growth is quite palatable in its native range cattle and buffalo grazing it kept it in check (Greenfield 1989).	ml	mh
18. Provides harbour?	Barbs on leaves can cut skin, and there is a belief in India that the plant restricts the movements of snakes as the barbs cut them (National Research Council 1993).	l	mh
Agriculture
19. Impact yield?	Planted in hedges along contour lines to reduce erosion and water run-off increasing soil moisture content and maintaining soil fertility without competing with the crop this practice is believed to increase yields (National Research Council 1993).	l	mh
20. Impact quality?	Planted in hedges along contour lines to reduce erosion and water run-off increasing soil moisture content and maintaining soil fertility without competing with the crop this practice is believed to increase yields (National Research Council 1993).	l	mh
21. Affect land value?	May increase value as enables more productive use of the land.	l	m
22. Change land use?	In Fiji it was used to limit erosion so that it was practical to cultivate sugar cane on slopes (National Research Council 1993).	l	m
23. Increase harvest costs?	Is alternative to more expensive engineering practices for erosion control and potentially a better option (National Research Council 1993).	l	mh
24. Disease host/vector?	Is related to other crop species such as maize and sorghum but reported to be generally pest and disease free except for some fungus’ which may attack the species during the wet season. (National Research Council 1993).	l	mh

Invasive

QUESTION	COMMENTS	RATING	CONFIDENCE
Establishment
1. Germination requirements?	The domesticated variety requires people to plant vegetative propagules, while the wild form of north India seedling will be produced under conditions of high humidity and high soil moisture (National Research Council 1993).	ml	mh
2. Establishment requirements?	Will not easily establish under shady conditions (National Research Council 1993).	ml	mh
3. How much disturbance is required?	Domesticated variety establishes where planted like a crop species, Wild variety is native to wetlands (Green field 1989)	mh	mh
Growth/Competitive
4. Life form?	Grass species, however without human intervention its is restricted to swamps and bogs making it a semi-aquatic attached emergent species (Green field 1989).	h	mh
5. Allelopathic properties?	None described and cropping species easily grow right up to it without significant decrease in yield (National Research Council 1993).	l	mh
6. Tolerates herb pressure?	Older growth avoided, however new growth is more palatable, and can be sustained even if cut back every two weeks (World Bank 1990).	mh	mh
7. Normal growth rate?	Been recorded to grow 5cm per day for more than 60 days, or reach 2m in height in a few months. Roots have been reported to grow 60cm deep in just 3 weeks. (National Research Council 1993).	h	mh
8. Stress tolerance to frost, drought, w/logg, sal. etc?	Native to swamps and bogs, tolerant of waterlogging, Deep rooted C₄ plant, tolerant of drought, Growth point below soil surface, tolerant of fire and grazing, Tolerant of pH as low as 4 and high as 11. Tolerant of salinity and will grow even if planted in solid bauxite. Only susceptible to freezing but can with stand temperatures as low as -10C (National Research Council 1993).	h	mh
Reproduction
9. Reproductive system	Domesticated variety spread through vegetative means (root division) however this is a slow process without human intervention, Described as a sod-forming grass. The wild variety does also produce seed. (National Research Council 1993).	h	mh
10. Number of propagules produced?	Only wild variety produces seed (National Research Council 1993).	m	mh
11. Propagule longevity?	Most study has been conducted on domesticated variety, which is believed not to produce fertile seed. It is however described to be similar to maize.	m	mh
12. Reproductive period?	Forms dense monocultures, Vetiver hedges in India have been purported to be at least 200 years old (National Research Council 1993).	h	mh
13. Time to reproductive maturity?	Will produce more tillers within first season, not reported when first sets seed but reported to grow to 2m within a few months almost its maximum height so could well flower within its first year however this is not specifically reported (National Research Council 1993).	h	mh
Dispersal
14. Number of mechanisms?	Mainly spread deliberately by people. Grows natively in swamps and bogs seed may therefore be spread by water.	mh	l
15. How far do they disperse?	Where seed set occurs seedlings described as adjacent or surrounding parent plant (National Research Council 1993).	ml	mh

References

Greenfield, J.C. (1989) Vetiver Grass (Vetiveria spp.) The Ideal Plant for Vegetative Soil and Moisture Conservation. In Vetiver Grass for Soil and Water conservation, Land Rehabilitation, and Embankment Stabilization. A collection of Papers and Newsletters Compiled by the Vetiver Network. World Bank. Washington, D.C.

National Research Council (1993) Vetiver Grass A thin green line against erosion. Board on Science and Technology for International Development. National academy Press. Washington D.C.

World Bank (1990) Vetiver Newsletter: Newsletter of the Vetiver Information Network, ASTAG, World Bank, Number 4, November 1990. In Vetiver Grass for Soil and

Water conservation, Land Rehabilitation, and Embankment Stabilization. A collection of Papers and Newsletters Compiled by the Vetiver Network. World Bank. Washington, D.C.

Global present distribution data references

Global Biodiversity Information Facility (GBIF) 2006, Global biodiversity information facility: Prototype data portal, viewed Aug 5 2006, http://www.gbif.org/

Missouri Botanical Gardens (MBG) 2006, w3TROPICOS, Missouri Botanical Gardens Database, viewed Aug 5 2006, http://mobot.mobot.org/W3T/Search/vast.html

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