Plant Assessment Form

Festuca perennis

Synonyms: Lolium multiflorum; Lolium perenne

Common Names: Italian ryegrass

Evaluated on: 1-Aug-03

List committee review date: 12/10/2017

Re-evaluation date:

Evaluator(s)

Joe DiTomaso
UC Davis
Weed Science Program, Robbins Hall, Univ. California, Davis CA 95616
530-754-8715
DiTomaso@vegmail.ucdavis.edu

List commitee members

Jake Sigg
Peter Warner
Doug Johnson
Joe DiTomaso
Brianna Richardson

General Comments

Removed second synonym, Lolium multiflorum, and added it to the synonym line, 3/24/17. Ramona Robison

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 2.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes B Observational
Impact?
Four-part score BBCD Total Score
B
1.2 ?Impact on plant community B. Moderate Observational
1.3 ?Impact on higher trophic levels C. Minor Other Published Material
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Other Published Material
Invasiveness?
Total Points
12 Total Score B
2.2 ?Local rate of spread with no management B. Increases less rapidly Observational
2.3 ?Recent trend in total area infested within state C. Stable Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
B. Moderate Other Published Material
2.5 ?Potential for human-caused dispersal A. High Other Published Material
2.6 ? Potential for natural long-distance dispersal C. Rare Observational
2.7 ?Other regions invaded C. Already invaded Other Published Material
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Other Published Material
Distribution?
Total Score A
3.2 ?Distribution/Peak frequency
(see Worksheet C)
A. High Other Published Material

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".

Section 1: Impact
Question 1.1 Impact on abiotic ecosystem processes? B Observational
Identify ecosystem processes impacted:

As an annual grass it likely increases fire frequency as do other annual grasses.


Sources of information:

Very little information, mostly observational by many people.


Question 1.2 Impact on plant community composition,
structure, and interactions?
B Observational
Identify type of impact or alteration:

Effect on native grassland plant communities significant but not as significant as medusahead or downy brome.


Sources of information:

Observational, many individuals.
Cadman, D. 2002. Ghost of aliens past : Influence of invasive annual grasses on vernal pool assemblages. Thesis, Sonoma State University, Rohnert Park, CA


Question 1.3 Impact on higher trophic levels? C Other Published Material
Identify type of impact or alteration:

Good forage species for livestock and wildlife. Impacats on other species mostly unknown. Can cause toxicity to livestock when associated with a fungus. Negative impacts on the native Plantago erecta, the sole source of food for the larvae of Bay checkerspot butterfly.


Sources of information:

DiTomaso, J.M. and E. A. Healy. 2005. Weeds of California. Div. Nat. Agr. Res. Univ. California (in press); Weiss, Stuart. 2003. CalEPPC Proceedings.


Question 1.4 Impact on genetic integrity? D Other Published Material

Hybridizes with other Lolium species, but no native Lolium occur in California.


Sources of information:

DiTomaso, J.M. and E. A. Healy. 2005. Weeds of California. Div. Nat. Agr. Res. Univ. California (in press)


Section 2: Invasiveness
Question 2.1 Role of anthropogenic and natural disturbance
in establishment?
B Observational
Describe role of disturbance:

Generally found in disturbed sites, but can move into relatively undisturbed grasslands.


Sources of information:

DiTomaso, J.M. and E. A. Healy. 2005. Weeds of California. Div. Nat. Agr. Res. Univ. California (in press)


Question 2.2 Local rate of spread with no management? B Observational
Describe rate of spread:

Similar rate of spread as other annual grasses, but probably less than awned grasses, such as medusahead and downy brome.


Sources of information:

DiTomaso, observational


Question 2.3 Recent trend in total area infested within state? C Observational
Describe trend:

So widespread that it is stable at this time. No unexposed habitat in the state.


Sources of information:

DiTomaso, observational


Question 2.4 Innate reproductive potential? B Other Published Material
Describe key reproductive characteristics:

Annual grass, produces numerous seed every year, cross and self pollinated, probably short leaved seed (<3 years).


Sources of information:

DiTomaso, J.M. and E. A. Healy. 2005. Weeds of California. Div. Nat. Agr. Res. Univ. California (in press)


Question 2.5 Potential for human-caused dispersal? A Other Published Material
Identify dispersal mechanisms:

Widely distributed in hay and still sold as seed.


Sources of information:

DiTomaso, J.M. and E. A. Healy. 2005. Weeds of California. Div. Nat. Agr. Res. Univ. California (in press)


Question 2.6 Potential for natural long-distance dispersal? C Observational
Identify dispersal mechanisms:

N long distance mechanism for transport of seed. Most seed probably fall close to parent plant.


Sources of information:

Observational, DiTomaso


Question 2.7 Other regions invaded? C Other Published Material
Identify other regions:

Very widespread around the world. Common agricultural weed and component of grasslands.


Sources of information:

Much literature on worldwide distribution of grass.


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Other Published Material

Mostly in grassland communities, but also found in some shaded and moist sites.


Sources of information:

CalFlora database indicated both non- and wetland habitats. Also listed in many floras.


Question 3.2 Distribution/Peak frequency? A Other Published Material
Describe distribution:

Very widespread and common.


Sources of information:

DiTomaso, J.M. and E. A. Healy. 2005. Weeds of California. Div. Nat. Agr. Res. Univ. California (in press)


Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter Yes
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually No
Seeds remain viable in soil for three or more years No
Viable seed produced with both self-pollination and cross-pollination Yes
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes No
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned No
Total points: 5
Total unknowns: 0
Total score: B?

Related traits:

Worksheet B - Arizona Ecological Types is not included here

Worksheet C - California Ecological Types

(sensu Holland 1986)
Major Ecological Types Minor Ecological Types Code?
Marine Systemsmarine systems
Freshwater and Estuarine lakes, ponds, reservoirs
Aquatic Systemsrivers, streams, canals
estuaries
Dunescoastal
desert
interior
Scrub and Chaparralcoastal bluff scrub
coastal scrub
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralA, > 50%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieA, > 50%
valley and foothill grasslandB, 20% - 50%
Great Basin grasslandC, 5% - 20%
vernal poolC, 5% - 20%
meadow and seep
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forest
riparian woodland
riparian scrub (incl.desert washes)B, 20% - 50%
Woodlandcismontane woodlandC, 5% - 20%
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forest
closed cone coniferous forest
lower montane coniferous forest
upper montane coniferous forest
subalpine coniferous forest
Alpine Habitatsalpine boulder and rock field
alpine dwarf scrub
Amplitude (breadth): A
Distribution (highest score): A

Infested Jepson Regions

Click here for a map of Jepson regions