Plant Assessment Form

Rytidosperma penicillatum

Synonyms: Danthonia pilosa R. Br.; Rytidosperma pilosum (R. Br.) Connor & Edgar

Common Names: hairy wallaby grass; hairy oat grass

Evaluated on: 5/19/11

List committee review date:

Re-evaluation date:

Evaluator(s)

Elizabeth Brusati, Science Program Manager
Cal-IPC
1442-A Walnut St. #462, Berkeley, CA 94709
510-843-3902
edbrusati@cal-ipc.org
Joseph M. DiTomaso, Specialist in Cooperative Extension
Dept. of Plant Sciences, University of California-Davis
Mail Stop 4, One Shields Ave., Davis CA 95616
530-754-8715
jmditomaso@ucdavis.edu

No list committee members listed

General Comments

According to the Jepson Online Interchange, this is the incorrect name for the species that is in California. It should be Rytidosperma clavatum (Zotov) Connor & Edgar. http://ucjeps.berkeley.edu/cgi-bin/get_cpn.pl?22327.
Previously known as Danthonia pilosa.

Table 2. Criteria, Section, and Overall Scores

Overall Score? Limited
Alert Status? No Alert
Documentation? 1.5 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U No Information
Impact?
Four-part score UCDU Total Score
C
1.2 ?Impact on plant community C. Minor Observational
1.3 ?Impact on higher trophic levels D. Negligible No Information
1.4 ?Impact on genetic integrity U. Unknown No Information
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
Invasiveness?
Total Points
7 Total Score C
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)
U. Unknown Other Published Material
2.5 ?Potential for human-caused dispersal C. Low Observational
2.6 ? Potential for natural long-distance dispersal C. Rare Other Published Material
2.7 ?Other regions invaded D. Not known anywhere else Observational
3.1 ?Ecological amplitude/Range
(see Worksheet C)
A. Widespread Observational
Distribution?
Total Score B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
D. Very low Observational

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? U No Information
Identify ecosystem processes impacted:

unknown


Sources of information:

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

Displaces native perennial grasses (e.g., Danthonia californica, Deschampsia cespitosa). Broad scale impacts unknown.


Sources of information:

Information reported by Peter Warner, Mendocino County, 12/9/2010


Question 1.3 Impact on higher trophic levels? D No Information
Identify type of impact or alteration:

Minor source of forage for animals. No other impacts known.


Sources of information:

Question 1.4 Impact on genetic integrity? U No Information

Potential for hybridization with native Danthonia californica.


Sources of information:

Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA enter text here


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

Occasionally invades areas with little or no natural disturbance


Sources of information:

Information reported by Peter Warner, Mendocino County, 12/9/2010


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

Not spreading to new sites, but existing populations are expanding


Sources of information:

Information reported by Peter Warner, Mendocino County, 12/9/201


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

Not spreading to new sites, but existing populations are expanding


Sources of information:

Information reported by Peter Warner, Mendocino County, 12/9/2010


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

Jepson Manual


Sources of information:

Uncertain about current means of dispersal; likely established during sheep grazing, perhaps deliberately introduced as forage at that time. No longer sold as a forage, so human-caused dispersal is likely minimal.


Question 2.5 Potential for human-caused dispersal? C Observational
Identify dispersal mechanisms:

Uncertain about current means of dispersal; likely established during sheep grazing, perhaps deliberately introduced as forage at that time. No longer sold as a forage, so human-caused dispersal is likely minimal.


Sources of information:

Information reported by Peter Warner, Mendocino County, 12/9/2010


Question 2.6 Potential for natural long-distance dispersal? C Other Published Material
Identify dispersal mechanisms:

Perhaps some movement on animals, but no natural long-distance dispersal mechanism.


Sources of information:

Joseph M. DiTomaso, personal communication. UC Davis.


Question 2.7 Other regions invaded? D Observational
Identify other regions:

Native to either Australia (Danthonia pilosa) or New Zealand (R. clavatum). No known areas where it has invaded other than northern California.


Sources of information:

GRIN; http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl


Section 3: Distribution
Question 3.1 Ecological amplitude/Range? A Observational

Listed as a _—“troublesome weed_— in rangelands in north coast counties in 1955 (Major 1955).
Coastal terrace prairie, coastal scrub, North Coast coniferous forest, valley and foothill grassland; Sonoma and Mendocino Counties, along immediate coast to about 3 miles inland (Warner 2010)


Sources of information:

Major 1955, Information reported by Peter Warner, Mendocino County, 12/9/2010


Question 3.2 Distribution/Peak frequency? D Observational
Describe distribution:

Sources of information:

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes
Dense infestations produce >1,000 viable seed per square meter No
Populations of this species produce seeds every year. Yes
Seed production sustained over 3 or more months within a population annually Unknown
Seeds remain viable in soil for three or more years Unknown
Viable seed produced with both self-pollination and cross-pollination Unknown
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 Yes
Total points: 3
Total unknowns: 3
Total score: U?

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 scrubD, < 5%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparralD, < 5%
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairie
valley and foothill grasslandD, < 5%
Great Basin grassland
vernal pool
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)
Woodlandcismontane woodland
piñon and juniper woodland
Sonoran thorn woodland
Forestbroadleaved upland forest
North Coast coniferous forestD, < 5%
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): B
Distribution (highest score): D

Infested Jepson Regions

Click here for a map of Jepson regions

  • Northwest