Plant Assessment Form

Ehrharta erecta

Synonyms: Ehrharta panicea SM., E. paniciformis Nees ex Trin., Panicum deflexum Guss., Trochera panicea Baill

Common Names: panic veldtgrass; Ehrharta; Lamarck's ehrharta; panic veld grass; Stebbin's grass

Evaluated on: 7/22/04

List committee review date: 27/08/2004

Re-evaluation date:

Evaluator(s)

Mark Frey, Ecologist
The Presidio Trust
34 Graham St./PO Box 29052/San Francisco, CA 94129
415-561-4148
mfrey@presidiotrust.gov

List commitee members

Joe DiTomaso
Peter Warner
Jake Sigg
John Randall
Alison Stanton
Cynthia Roye

General Comments

No general comments for this species

Table 2. Criteria, Section, and Overall Scores

Overall Score? Moderate
Alert Status? No Alert
Documentation? 2 out of 5
Score Documentation
1.1 ?Impact on abiotic ecosystem processes U
Impact?
Four-part score UACD Total Score
B
1.2 ?Impact on plant community A. Severe Observational
1.3 ?Impact on higher trophic levels C. Minor Anecdotal
1.4 ?Impact on genetic integrity D. None Other Published Material
2.1 ?Role of anthropogenic and natural disturbance in establishment B. Moderate Observational
Invasiveness?
Total Points
15 Total Score B
2.2 ?Local rate of spread with no management A. Increases rapidly Observational
2.3 ?Recent trend in total area infested within state A. Increasing rapidly Observational
2.4 ?Innate reproductive potential
(see Worksheet A)
A. High Other Published Material
2.5 ?Potential for human-caused dispersal B. Moderate 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 B
3.2 ?Distribution/Peak frequency
(see Worksheet C)
C. 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
Identify ecosystem processes impacted:

Sources of information:

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

Outcompetes native grasses and herbs. Increases litter accumulation, which is the mechanism of competitive exclusion.


Sources of information:

Observational, Mark Frey.
McIntyre, S. and PY Ladiges. 1985. Aspecs of the biology of Ehrharta erecta Weed Research. 25:21-32.
Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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

Reduces available native forage. No real information exists on its direct impacts. Response based on displacement of native plant spp and food sources for native wildlife.


Sources of information:

Anectdotal.


Question 1.4 Impact on genetic integrity? D Other Published Material

No closely related CA natives.


Sources of information:

Hickman, JC. 1993. The Jepson Manual: Higher Plants of California. UC Press
Observational, Mark Frey.


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

Facilitated by shade and moisture. Readily moves into gaps formed by tree fall and spread by mowing.


Sources of information:

Observational, Mark Frey.
McIntyre, S. and PY Ladiges. 1985. Aspecs of the biology of Ehrharta erecta Weed Research. 25:21-32.
Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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

Rapidly spreads and perniciously persists.


Sources of information:

Observational, Mark Frey.
Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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

Expanding throughouth the state.


Sources of information:

Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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

Matures rapidly, sets many seeds, sets seed for an extended period. 7 pts


Sources of information:

McIntyre, S. and PY Ladiges. 1985. Aspecs of the biology of Ehrharta erecta Weed Research. 25:21-32.
Sigg, J. 1996. Ehrharta erecta: Sneak attack in the making? CalEPPC News 4(3):8-9.
Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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

Can attach to boots in mud. Mowing aids establishment and dispersal.


Sources of information:

Sigg, J. 1996. Ehrharta erecta: Sneak attack in the making? CalEPPC News 4(3):8-9.


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

Unlikely except on rare occasions. Can be spread by moving water.


Sources of information:

Observational, Mark Frey.
Observational, Peter Warner, 2004.


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

Europe, Northern Africa, Australia.


Sources of information:

McIntyre, S. and PYLadiges. 185. Aspects of the biology of Ehrharta ereca Lam. Weed Research. 25: 21-32.
Ricciardi, M and B Anazalone. 1988. Ehrharta erecta Graminea in Italy. Webbia. 42(2): 145-152.
Scott, JK and ES Del Fosse. 1992. Southern African plants naturalized in Australia: A review of weed status and biological control potential. Plant Protection Quarterly. 7(2): 70-80.


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

Invades a wide variety of habitats throughout the central coast and southern California. Invades 5 major and 9 minor ecotypes in CA.


Sources of information:

Muns, B. ND. Updates to Lower Eaton Canyon, San Gabriel Mts For a: A checklish of the vascular plants. http://tchester.org/sgm/plants/floras/lower_eaton_canyon_updates.html.
Top 20 Pest Plants in the East Bay, East Bay California Native Plant Society. www.ebcnps.org
Vascular plants of Bodega Head & Bodega Dunes. www.bml.ucdavis.edu/bmr/PLNTLST.pdf. Accessed July 23, 2004.
Hickman, J (ed.). 1993. The Jepson Manual: Higher plants of California. UC Press, Berkeley.
Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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

Invades 5-20% of coastal bluff scrub and coastal scrub.


Sources of information:

Observational, Joe DiTomaso, Peter Warner, Cynthia Roye, Jake Sigg, John Randall, Alison Stanton, 2004.


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 Yes
Seeds remain viable in soil for three or more years No
Viable seed produced with both self-pollination and cross-pollination Unknown
Has quickly spreading vegetative structures (rhizomes, roots, etc.) that may root at nodes Yes
Fragments easily and fragments can become established elsewhere No
Resprouts readily when cut, grazed, or burned Yes
Total points: 7
Total unknowns: 1
Total score: A?

Related traits:

Shade tolerant, often (not always) foundin moist areas, seeds throughout the rainy season or year-round if irrigated.

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
DunescoastalD, < 5%
desert
interior
Scrub and Chaparralcoastal bluff scrubC, 5% - 20%
coastal scrubC, 5% - 20%
Sonoran desert scrub
Mojavean desert scrub (incl. Joshua tree woodland)
Great Basin scrub
chenopod scrub
montane dwarf scrub
Upper Sonoran subshrub scrub
chaparral
Grasslands, Vernal Pools, Meadows, and other Herb Communitiescoastal prairieD, < 5%
valley and foothill grassland
Great Basin grassland
vernal pool
meadow and seepD, < 5%
alkali playa
pebble plain
Bog and Marshbog and fen
marsh and swamp
Riparian and Bottomland habitatriparian forestD, < 5%
riparian woodlandD, < 5%
riparian scrub (incl.desert washes)D, < 5%
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): A
Distribution (highest score): C

Infested Jepson Regions

Click here for a map of Jepson regions

  • Central West
  • Desert Province
  • Mojave Desert
  • Sonoran Desert
  • Great Valley
  • Northwest
  • Southwest