Ventenata dubia_Steve Matson
Photo by Steve Matson

Ventenata dubia Risk Assessment

Common names: North Africa grass

Ventenata dubia -- California

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Evaluation Summary
Summary: 
General Evaluation Information
Date of Evaluation: 
March 23, 2016
Evaluation Time (hrs): 
1 Hour
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: 
Very High
Answer / Justification: 
Present in 8 California counties, as well as 10 other US states and four Canadian provinces. No information on the USDA GRIN website. GBIF also shows a couple points in Japan and northern Europe outside its native range.
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: 
Very High
Answer / Justification: 
Present in 8 California counties, as well as several other US states that are similar to California.
Reference(s): 
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: 
Not on any US noxious weed list. However, Ventenata is beginning to replace perennial grasses and forbs along roadsides and in hay, pasture, range and CRP fields in the western U.S. In addition to having minimal forage value for livestock or wildlife, ventenata is also undesirable because its shallow root system may cause the soil to be more prone to erosion. Over time, decline of productivity and land value occurs. In the western U.S., ventenata is beginning to receive a great deal of attention due to its rate of spread and difficulty in control.
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: 
Not on any US noxious weed list. However, Ventenata is beginning to replace perennial grasses and forbs along roadsides and in hay, pasture, range and CRP fields in the western U.S (including areas that are similar to California). In addition to having minimal forage value for livestock or wildlife, ventenata is also undesirable because its shallow root system may cause the soil to be more prone to erosion. Over time, decline of productivity and land value occurs. In the western U.S., ventenata is beginning to receive a great deal of attention due to its rate of spread and difficulty in control.
Reference(s): 
5. Are other species of the same genus (or closely related genera) invasive in a similar climate?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
The Global Compendium of Weeds has only one entry for one other species of Ventenata. However, its synonym genus is Avena and Avena barbata and Avena fatua are both invasive in California.
6. Is the species (or cultivar or variety) found predominately in a climate matching the region of concern?
Yes or No: 
Yes
Points: 
2
Confidence Level: 
High
Answer / Justification: 
Its native range is southern Europe, western Asia, and northern Africa, which are areas with a high overlap with California. The western US states where it has naturalized also have good overlap with California's climate. GBIF map = http://www.gbif.org/species/2703592
Reference(s): 
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: 
Ventenata is beginning to replace perennial grasses and forbs along roadsides and in hay, pasture, range and CRP fields in the western U.S. Yes for displacing the plant community but the description does not say that it overtops or smothers them.
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: 
No mention of this as one of its impacts. Not listed in the USDA Fire Effects Information System database. Defaulting to no due to lack of information.
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: 
Can be grazed but has minimal forage value and later in the season the stems harden and become unpalatable. Ventenata is beginning to replace perennial grasses and forbs along roadsides and in hay, pasture, range and CRP fields in the western U.S. In addition to having minimal forage value for livestock or wildlife, ventenata is also undesirable because its shallow root system may cause the soil to be more prone to erosion. Over time, decline of productivity and land value occurs.
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: 
Very High
Answer / Justification: 
Grows only 10-46cm high, so no.
Reference(s): 
Reproductive Strategies
11. Does this species (or cultivar or variety) reproduce and spread vegetatively?
Yes or No: 
No
Points: 
0
Confidence Level: 
Very High
Answer / Justification: 
Reproduces by seed. No indication of vegetative reproduction.
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: 
No
Points: 
0
Confidence Level: 
Very High
Answer / Justification: 
No indication of this in the NRCS factsheet and it seems unlikely for an annual grass such as this.
Reference(s): 
13. Does the species (or cultivar or variety) commonly produce viable seed?
Yes or No: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Yes, 15-35 per plant.
Reference(s): 
14. Does this plant produce copious viable seeds each year (> 1000)?
Yes or No: 
No
Points: 
0
Confidence Level: 
Very High
Answer / Justification: 
About 15 – 35 seeds are produced 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: 
Medium
Answer / Justification: 
Ventenata is a winter annual that germinates in the fall when temperatures are moderate to high. No indication of dormancy requirements.
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: 
Very High
Answer / Justification: 
An annual grass, so must produce in its first (only) year.
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: 
Seed heads are produced May and June, according to USDA. Flowering time in California is June-September, according to Jepson. Using the California months, I am extrapolating to more than three months seed production.
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: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
It can be spread by humans and animals due to having long awns.
Reference(s): 
19. Are the plant’s propagules frequently dispersed long distance (>100 m) by wind or water?
Yes or No: 
No
Points: 
0
Confidence Level: 
Very Low
Answer / Justification: 
There is no mention of this in the NRCS factsheet. Uncertain but scored as No by default.
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: 
Yes
Points: 
1
Confidence Level: 
Very High
Answer / Justification: 
Ventenata is spread primarily as a contaminant of Kentucky bluegrass, hay and annual crops. In addition, ventenata is found along roadsides and likely is moved along the transportation corridors where it has opportunities to move into surrounding areas. It can also be spread by humans and animals due to having long awns.
Reference(s): 
Evaluation Notes

USDA PLANTS: http://plants.usda.gov/core/profile?symbol=VEDU

Jepson: http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=47815

Much of this evaluation comes from a factsheet on the USDA PLANTS website written by staff from the USDA Pullman Plant Materials Center.

Reviewed by Eric Wrubel, Golden Gate National Recreation Area

Total PRE Score

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

PRE Score: 
19
Number of questions answered: 
20
Screener Confidence (%): 
84.0
PRE Content Access and Privacy
Evaluation visibility: 
Public - accessible to all site users

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