Source: California Invasive Plant Council


URL of this page: http://www.cal-ipc.org/site/paf/327
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Cal-IPC Plant Assessment Form

For use with "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands"
by the California Invasive Plant Council and the Southwest Vegetation Management Association

Table 1. Species and Evaluator Information

Species name
(Latin binomial):
The official Latin binomial name for this species. Specify only one name here. Additional species names may go into the Synonyms field.

Dittrichia graveolens

Synonyms:
Additional Latin binomial names for this species. Separate multiple names with a ; character. Please avoid narrative descriptions, and list only the binomial names.
Inula graveolens, Erigeron graveolens, Cupularia graveolens
Common names:
Common names for this species. Separate multiple names with a ; character.
stinkwort; stinkweed; Khaki weed;
Evaluation date:
The date(s) when this species PAF was filled out, modified, or reviewed. This is free-form text, so it may include multiple dates or other notes.
04/14/05
Evaluator #1 John Beall
California Native Plant Society
1275 Heatherstone WaySunnyvale, CA 94087
408-739-3756
bpsdeuc@yahoo.co,
List committee members: Jake Sigg, Peter Warner, Bob Case, John Knapp, Elizabeth Brusati
Committee review date: 7/8/05
List date:
Re-evaluation date(s):
General comments
on this assessment:
Enter any additional notes about this assessment, such as factors affecting the reliability or completeness of the answers, likely affects of impacts, or research which is not specific to California but is still relevant in the evaluation of this species.
Dittrichia graveolens is very new to California (1984). It has been found primarily in disturbed areas. Conclusions about which plant communities (intact or disturbed) can be invaded by Dittrichia graveolens in California are speculative. Future specimens collected should include observations of the plant community (species present) and the condition of the plant community.

Table 2. Criteria, Section, and Overall Scores

Overall Score

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistribution
AA BAnyHighNo Alert
AC DAnyModerateAlert
BA BA BModerateNo Alert
BA BC DModerateAlert
BC DAnyLimitedNo Alert
CAA BModerateNo Alert
CAC DLimitedNo Alert
CBAModerateNo Alert
CBB DLimitedNo Alert
CCAnyLimitedNo Alert
DAnyAnyNot ListedNo Alert

Moderate

Alert Status

Plant scoring matrix
Based on letter scores from Sections 1 through 3 below

ImpactInvasivenessDistributionAlert
AA or BC or DAlert
BA or BC or DAlert

Alert

Documentation

The total documentation score is the average
of Documentation scores given in Table 2.

Reviewed Scientific Publication4 points
Other Published Material3 points
Observational2 points
Anecdotal1 points
Unknown or No Information0 points

3 out of 5

Score Documentation
1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
U. Unknown
Impact
Section 1 Scoring Matrix
Q 1.1Q 1.2Q 1.3Q 1.4Score
AAAnyAnyA
ABA,BAnyA
ABC,D,UAnyB
AC,D,UAnyAnyB
BAAAnyA
BABAA
BAB,CB-D,UB
BAC,D,UAA
BAC,D,UB-D,UB
BBAAA
BC,D,UAAB
BB-DAB-D,UB
BB-DB-D,UAnyB
BD,UC,D,UA-BB
BD,UC,D,UC,D,UC
C-D,UAAAnyA
CBAAnyB
CA,BB-D,UAnyB
CC,D,UAnyAnyC
DA,BBAnyB
DA,BC,D,UAnyC
DCAnyAnyC
DD,UAnyAnyD
UAB,CAnyB
UB,CA,BAnyB
UB,CC,D,UAnyC
UUAnyAnyU


Four-part score
UBBD

Total Score
B
1.2 Impact on plant community
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
B. Moderate Other Published Material
1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
B. Moderate Other Published Material
1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
D. None Other Published Material
2.1 Role of anthropogenic and natural disturbance in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
B. Moderate Other Published Material
Invasiveness
Section 2 Scoring Matrix
Total pointsScore
17-21A
11-16B
5-10C
0-4D
More than two U’sU


Total Points
18

Total Score
A
2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
A. Increases rapidly Reviewed Scientific Publication
2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
A. Increasing rapidly Reviewed Scientific Publication
2.4 Innate reproductive potential
(see Worksheet A)
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
A. High Other Published Material
2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
A. High Reviewed Scientific Publication
2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
A. Frequent Other Published Material
2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
C. Already invaded Other Published Material
3.1 Ecological amplitude/Range
(see Worksheet C)
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
B. Moderate Other Published Material
Distribution
Section 3 Scoring Matrix
Q 3.1Q 3.2Score
AA, BA
AC,D,UB
BAA
BB,CB
BDC
CA,BB
CC,DC
DAB
DB,CC
DDD
A,BUC
C,DUD
UUU


Total Score
C
3.2 Distribution/Peak frequency
(see Worksheet C)
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
D. Very low Other Published Material

Table 3. Documentation

Scores are explained in the "Criteria for Categorizing Invasive Non-Native Plants that Threaten Wildlands".
Short citations may be used in this table. List full citations at end of this table.

Section 1: Impact

U Question 1.1 Impact on abiotic ecosystem processes
Consider the impact on the natural range and variation of abiotic ecosystem processes and system-wide parameters in ways that significantly diminish the ability of native species to survive and reproduce. Alterations that determine the types of communities that can exist in a given area are of greatest concern. Examples of abiotic processes include:
- fire occurrence, frequency, and intensity;
- geomorphological changes such as erosion and sedimentation rates;
- hydrological regimes, including soil water table;
- nutrient and mineral dynamics, including salinity, alkalinity, and pH;
- light availability (e.g. when an aquatic invader covers an entire water body that would otherwise be open).

Select the one letter below that best describes this species’ most severe impact on an abiotic ecosystem process:
A. Severe, possibly irreversible, alteration or disruption of an ecosystem process.
B. Moderate alteration of an ecosystem process.
C. Minor alteration of an ecosystem process.
D. Negligible perceived impact on an ecosystem process.
U. Unknown.
Identify ecosystem processes impacted:
Dittrichia graveolens can grow on heavy metal mine waste adding litter to the soil and bioaccumulating Mercury, Zinc, and Nickel. This could possibly redistribute heavy metals from deeper in the soil profile and accumulate them in the growing region of plants. There is no information to support this hypothesis, however. Dittrichia graveolens can grow on mercury mine waste soil with 2.5% Mercury (Hg), and bioaccumulate 16,500ug/g Hg (Almaden mine, Spain). It has grown on mine waste in Rubik, Albania and bioaccumulates Nickel (1110 mg/kg and Zinc (849 mg/kg).

Sources of information:
Danish Environmental Protection Agency. 2000. Management of Contaminated Sites and Land in Central and Eastern Europe: Albania Accessed online April 4, 2005 at http://www.mst.dk/udgiv/Publications/2000/87-7909-888-6/html/kap10-eng.htm Higueras, Pablo L. University of Castilla-La-Mancha, Spain. 2003. Presentation: Almaden: Remediation techniques in the largest mercury mining district of the world. CCMS Meeting Prevention and Remediation Issues in selected Industrial Sectors Pilot Study. Bala Mare (Romania), Sept. 7-11 2003. Accessed online April 4, 2005 at http://www.cluin.org/romania/presentations/2921843.pdf

Other Published Material B Question 1.2 Impact on plant community composition,
structure, and interactions
Consider the cumulative ecological impact of this species to the plant communities it invades. Give more weight to changes in plant composition, structure, and interactions that involve rare or keystone species or rare community types. Examples of severe impacts include:
- formation of stands dominated (>75% cover) by the species;
- occlusion (>75% cover) of a native canopy, including a water surface, that eliminates or degrades layers below;
- significant reduction or extirpation of populations of one or more native species.

Examples of impacts usually less than severe include:
- reduction in propagule dispersal, seedling recruitment, or survivorship of native species;
- creation of a new structural layer, including substantial thatch or litter, without elimination or replacement of a pre-existing layer;
- change in density or depth of a structural layer;
- change in horizontal distribution patterns or fragmentation of a native community;
- creation of a vector or intermediate host of pests or pathogens that infect native plant species.

Select the one letter below that best describes this species’ impact on community composition, structure and interactions:
A. Severe alteration of plant community composition, structure, or interactions.
B. Moderate alteration of plant community composition.
C. Minor alteration of community composition.
D. Negligible impact known; causes no perceivable change in community composition, structure, or interactions.
U. Unknown.
Identify type of impact or alteration:
Can form dense stands in late summer/early fall with few plant competitors. Grows rapidly late in the year from small rossette to over 1meter tall in open, disturbed, riparian, non-native grasslands, and sites which may include some native species. In Australia: Can compete with annuals and forbs. Dittrichia graveolens impacts a greater variety of plant communities.

Sources of information:
Australia: Victoria (Australia) Department of Primary Industries. 2005. Impact Assessment Dittrichia graveolens. Accessed online on 4/6/05 at http://www.nre.vic.gov.au/DPI/Vro/rosite.nsf/pages/impact_stinkwort Parsons, W. T., Cuthbertson, E.G. 1992. Stinkwort Dittrichia graveolens (L.) Noxious Weeds of Australia Inkata Press p 281-283. Parsons, W. T., 1973 Stinkwort (Inula graveolens (L.) Desf.) Noxious Weeds of Victoria. Inkata Press. Sydney Australia p104-107. California: Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. Parsons, W. T., 1973 Stinkwort (Inula graveolens (L.) Desf.) Noxious Weeds of Victoria. Inkata Press. Sydney Australia p104-107. John Beall: personal observation (2000-2005)

Other Published Material B Question 1.3 Impact on higher trophic levels
Consider the cumulative impact of this species on the animals, fungi, microbes, and other organisms in the communities that it invades. Although a non-native species may provide resources for one or a few native species (e.g. by providing food, nesting sites, etc.), the ranking should be based on the species’ net impact on all native species. Give more weight to changes in composition and interactions involving rare or keystone species or rare community types.
Examples of severe impacts include:
- extirpation or endangerment of an existing native species or population;
- elimination or significant reduction in native species’ nesting or foraging sites, cover, or other critical resources (i.e., native species habitat), including migratory corridors.

Examples of impacts that are usually less than severe include:
- minor reduction in nesting or foraging sites, cover, etc. for native animals;
- minor reduction in habitat connectivity or migratory corridors;
- interference with native pollinators;
- injurious components, such as awns or spines that damage the mouth and gut of native wildlife species, or production of anti-digestive or acutely toxic chemical that can poison native wildlife species.

Select the one letter below that best describes this species’ impact on community composition and interactions:
A. Severe alteration of higher trophic populations, communities, or interactions.
B. Moderate alteration of higher trophic level populations, communities, or interactions.
C. Minor alteration of higher trophic level populations, communities or interactions.
D. Negligible impact; causes no perceivable change in higher trophic level populations, communities, or interactions.
E. Unknown.
Identify type of impact or alteration:
Sheep graze on plant seedheads can get sick or die. Can taint meat or milk if eaten by cows. Can cause contact dermatitis/itching to people brushing against or hand pulling (without gloves) green plants. The barbed seedhead becomes imbedded in the intestine of sheep causing enteritis. The plants produce terpenes which are thought to cause allergic contact dermititis.

Sources of information:
In Australia Philbey, A.W., A.G. Morton, 2000. Pyogranulomatous enteristis in sheep due to penetrating seed heads of Dittrichia graveolens. Aust. Vet. J. Vol. 78. No 12 pps 858-860 Parsons, W. T., 1973 Stinkwort (Inula graveolens (L.) Desf.) Noxious Weeds of Victoria. Inkata Press. Sydney Australia p104-107. Parsons, W. T., Cuthbertson, E.G. 1992. Stinkwort Dittrichia graveolens (L.) Noxious Weeds of Australia Inkata Press p 281-283. In California Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. John Beall : personal observation (2000-2005)

Other Published Material D Question 1.4 Impact on genetic integrity
Consider whether the species can hybridize with and influence the proportion of individuals with non-native genes within populations of native species. Mechanisms and possible outcomes include:
- production of fertile or sterile hybrids that can outcompete the native species;
- production of sterile hybrids that lower the reproductive output of the native species.

Select the one letter below that best describes this species’ impact on genetic integrity:
A. Severe (high proportion of individuals).
B. Moderate (medium proportion of individuals).
C. Minor (low proportion of individuals).
D. No known hybridization.
U. Unknown.
Identify impacts:
None No native species of Dittrichia

Sources of information:
Hickman, J. C. (ed.) 1993. The Jepson Manual, Higher Plants of California. University of California Press. Berkeley, CA

Section 2: Invasiveness

Other Published Material B Question 2.1 Role of anthropogenic and natural disturbance
in establishment
Assess this species’ dependence on disturbance—both human and natural—for establishment in wildlands. Examples of anthropogenic disturbances include:
- grazing, browsing, and rooting by domestic livestock and feral animals;
- altered fire regimes, including fire suppression;
- cultivation;
- silvicultural practices;
- altered hydrology due to dams, diversions, irrigation, etc.;
- roads and trails;
- construction;
- nutrient loading from fertilizers, runoff, etc.

Examples of natural disturbance include:
- wildfire;
- floods;
- landslides;
- windthrow;
- native animal activities such as burrowing, grazing, or browsing.

Select the first letter in the sequence below that describes the ability of this species to invade wildlands:
A. Severe invasive potential—this species can establish independent of any known natural or anthropogenic disturbance.
B. Moderate invasive potential—this species may occasionally establish in undisturbed areas but can readily establish in areas with natural disturbances.
C. Low invasive potential—this species requires anthropogenic disturbance to establish.
D. No perceptible invasive potential—this species does not establish in wildlands (though it may persist from former cultivation).
U. Unknown.
Describe role of disturbance:
Anthropogenic disturbances such as: timing/type of weed control, general construction/grading of lots, right of ways, roads, trails, levees, and dams. Overgrazing domestic livestock and improperly timed mowing can encourage establishment. So far Dittrichia graveolens needs some anthropogenic or natural disturbance to invade native plant communities. Removal of vegetation encourages establishment of Dittrichia graveolens.

Sources of information:
Australia Parsons, W. T., Cuthbertson, E.G. 1992. Stinkwort Dittrichia graveolens (L.) Noxious Weeds of Australia Inkata Press p 281-283. Parsons, W. T., 1973 Stinkwort (Inula graveolens (L.) Desf.) Noxious Weeds of Victoria. Inkata Press. Sydney Australia p104-107. Victoria (Australia( Department of Primary Industries. 2005. Impact Assessment Dittrichia graveolens. Accessed online on 4/6/05 at http://www.nre.vic.gov.au/DPI/Vro/rosite.nsf/pages/impact_stinkwort California Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203.

Reviewed Scientific Publication A Question 2.2 Local rate of spread with no management
Assess this species’ rate of spread in existing localized infestations where the proportion of available habitat invaded is still small when no management measures are implemented.

Select the one letter below that best describes the rate of spread:
A. Increases rapidly (doubling in <10 years)
B. Increases, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe rate of spread:
Rapidly expanding. Dittrichia graveolens was found in California first in 1984 in Alviso in Santa Clara County (Close to Alameda County) along a levee/railroad track. Since that time it has rapidly expanded along roadsides, bayland levees, manipulated riparian areas, vacant lots, overgrazed pastures, and non-native grasslands from Santa Clara, Alameda, and Contra Costa Counties to surrounding counties.

Sources of information:
Hrusa, Fred; Ertter, Barbara;Sanders, Andrew; Leppeig, Gordon; Dean Ellen. 2002. Catalogue of non-native vascular plants occurring in spontaneously in California beyound those addressed in The Jepson Manual:Part I. Madrono. 49(20 April-June 61-98. Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. Preston, Robert List of Dittricha graveolens specimens. unpublished document. Jepson Herbarium Dittrichia graveolens, specimens. John Beall: Personal observation

Reviewed Scientific Publication A Question 2.3 Recent trend in total area infested within state
Assess the overall trend in the total area infested by this species statewide. Include current management efforts in this assessment and note them.

Select the one letter below that best describes the current trend:
A. Increasing rapidly (doubling in total range statewide in <10 years)
B. Increasing, but less rapidly
C. Stable
D. Declining
U. Unknown
Describe trend:
Increasing rapidly since introduction in 1984 in disturbed areas primarliy along roads, levees, and manipulated rivercourses. Dittrichia graveolens is found (based upon a ID'ed specimen) in 14 counties in California. Specimens were collected and ID'ed in Santa Clara County (1984), Alameda County (1996), Contra Costa County (1996), Madera County (1997), San Joaquin County (1997), Solano County (1998), Sonoma County (1999), YoloCounty (1999), San Mateo County (2001), Marin County (2002), Sacramento County (2002), Santa Cruz County (2002), Placer County (2003), San Diego County (2003). Counties where specimens have not been seen and/or listed, but not collected and ID'ed include San Benito County (2004) Ventura County (2004), Monterey County (2005)

Sources of information:
Hrusa, Fred; Ertter, Barbara;Sanders, Andrew; Leppeig, Gordon; Dean Ellen. 2002. Catalogue of non-native vascular plants occurring in spontaneously in California beyound those addressed in The Jepson Manual:Part I. Madrono. 49(20 April-June 61-98. Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. Preston, Robert List of Dittricha graveolens specimens and locations. unpublished document. Pinnacles Plant Checklist December 2004 unpublished document. Jepson Herbarium Dittrichia graveolens specimens Bob Case: personal communication (2005) John Beall: personal observation (2005)

Other Published Material A Question 2.4 Innate reproductive potential
Assess the innate reproductive potential of this species. Worksheet A is provided for computing the score.
Describe key reproductive characteristics:
. Plants growing from 2 centimeters to one meter can produce flowers. Dittrichia graveolens produces copius amounts of seed ( estimated 15,000 seed per plant) after a rapid growth from rosette in late summer. It flowers from September till December with seeds developing after flowering even after plant being pulled. Seeds last no more than three years. Seeds can move over 200 meters in the air.

Sources of information:
Parsons, W. T., Cuthbertson, E.G. 1992. Stinkwort Dittrichia graveolens (L.) Noxious Weeds of Australia Inkata Press p 281-283. Parsons, W. T., 1973 Stinkwort (Inula graveolens (L.) Desf.) Noxious Weeds of Victoria. Inkata Press. Sydney Australia p104-107. Victoria (Australia) Department of Primary Industries. 2005. Invasiveness Assessment Dittrichia graveolens. Accessed online on 4/6/05 at http://www.nre.vic.gov.au/DPI/Vro/rosite.nsf/pages/_stinkwort Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. John Beall: Personal observation (2000-2005)

Reviewed Scientific Publication A Question 2.5 Potential for human-caused dispersal
Assess whether this species is currently spread—or has high potential to be spread—by direct or indirect human activity. Such activity may enable the species to overcome natural barriers to dispersal that would not be crossed otherwise, or it may simply increase the natural dispersal of the species. Possible mechanisms for dispersal include:
- commercial sales for use in agriculture, ornamental horticulture, or aquariums;
- use as forage, erosion control, or revegetation;
- presence as a contaminant (seeds or propagules) in bulk seed, hay, feed, soil, packing materials, etc.;
- spread along transportation corridors such as highways, railroads, trails, or canals;
- transport on boats or boat trailers.

Select the one letter below that best describes human-caused dispersal and spread:
A. High—there are numerous opportunities for dispersal to new areas.
B. Moderate—human dispersal occurs, but not at a high level.
C. Low—human dispersal is infrequent or inefficient.
D. Does not occur.
U. Unknown.
Identify dispersal mechanisms:
Dittrichia graveolens has a wide variety of human caused dispersal mthods Dittrichia graveolens seeds can be dispersed long distances by the barbed/sticky seed attaching to vehicles, human clothing, shoes, or animal fur. Sheep or unprocessed wool can carry seeds. Seeds can be moved with soil in loads or with equiptment. Seeds can be windborne over 200 meters which facilitates movement by human causes.

Sources of information:
Parsons, W.T. 1973 Noxious Weeds of Victoria. Inkata Press Sydney Australia, Parsons, W. T., Cuthbertson, E.G. 1992. Stinkwort Dittrichia graveolens (L.) Noxious Weeds of Australia Inkata Press p 281-283. Victoria (Australia) Department of Primary Industries. 2005. Impact Assessment Dittrichia graveolens. Accessed online on 4/6/05 at http://www.nre.vic.gov.au/DPI/Vro/rosite.nsf/pages/_stinkwort DiTomaso J., Healey E., Weeds of California and other Western States. unpublished. Preston, R.E. 1997, Dittrichia graveolens (Asteraceae), New to California weed flora. Madrono 44(2). 200-203. Randall, John. 1999, Import Risk Analysis: Importation of weed species by live animals and unprocessed fibre of sheep and goats. p. 13 Ministry of Agriculture and Forestry. Wellington New Zealand. Nesom G. L. 2004. Asteraceae from wool mill sites in South Carolina, Including new records for North America. SIDA 21(2) 1215-1223.

Other Published Material A Question 2.6 Potential for natural long-distance dispersal
We have chosen 1 km as the threshold of "long-distance." Assess whether this species is frequently spread, or has high potential to be spread, by animals or abiotic mechanisms that can move seed, roots, stems, or other propagules this far. The following are examples of such natural long-distance dispersal mechanisms:
- the species’ fruit or seed is commonly consumed by birds or other animals that travel long distances;
- the species’ fruits or seeds are sticky or burred and cling to feathers or hair of animals;
- the species has buoyant fruits, seeds, or other propagules that are dispersed by flowing water;
- the species has light propagules that promote long-distance wind dispersal;
- The species, or parts of it, can detach and disperse seeds as they are blown long distances (e.g., tumbleweed).

Select the one letter below that best describes natural long-distance dispersal and spread:
A. Frequent long-distance dispersal by animals or abiotic mechanisms.
B. Occasional long-distance dispersal by animals or abiotic mechanisms.
C. Rare dispersal more than 1 km by animals or abiotic mechanisms.
D. No dispersal of more than 1 km by animals or abiotic mechanisms.
U. Unknown.
Identify dispersal mechanisms:
Seed can be moved naturally by wind, soil movement, water, and seed attachment to animals. Pappus is well developed for wind dispersal and can move seed long distances. Seeds can be dispersed by wind greater than 200 meters which facilitates other natural dispersal mechanisms. Dispersal by attachement of seed to animals. Seeds can be moved by water into roadless area more than two miles down Chalone Creek at Pinnacles National Monument.

Sources of information:
Victoria (Australia) Department of Primary Industries. 2005. Invasiveness Assessment Dittrichia graveolens. Accessed online on 4/6/05 at http://www.nre.vic.gov.au/DPI/Vro/rosite.nsf/pages/_stinkwort :Parsons, W. T., Cuthbertson, E.G. 1992. Stinkwort Dittrichia graveolens (L.) Noxious Weeds of Australia Inkata Press p 281-283. Parsons, W. T., 1973 Stinkwort (Inula graveolens (L.) Desf.) Noxious Weeds of Victoria. Inkata Press. Sydney Australia p104-107. California: Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. Sharon Franklet Botanist, Pinnacles National Monument: Personal Communication (2005)

Other Published Material C Question 2.7 Other regions invaded
Assess whether this species has invaded ecological types in other states or countries outside its native range that are analogous to ecological types not yet invaded in your state (see Worksheets B, C, and D for California, Arizona, and Nevada, respectively, in Part IV for lists of ecological types). This information is useful in predicting the likelihood of further spread within your state.

Select the one letter below that best describes the species' invasiveness in other states or countries, outside its native range.
A. This species has invaded 3 or more ecological types elsewhere that exist in your state and are as yet not invaded by this species (e.g. it has invaded Mediterranean grasslands, savanna, and maquis in southern Europe, which are analogous to California grasslands, savanna, and chaparral, respectively).
B. Invades 1 or 2 ecological types that exist but are not yet invaded in your state.
C. Invades elsewhere but only in ecological types that it has already invaded in the state.
D. Not known as an escape anywhere else.
U. Unknown.
Identify other regions:
See Rationale Besides being found in California, Dittrichia graveolens is found in New Jersey at Liberty State Park, New York, Connecticut, and in 1957 a specimen was found, but not identified until 200, in Berkeley County, South Carolina. All United States locations were considered disturbed, ruderal, rangeland, tidal, or riparian. In Australia which has had Dittrichia for 150 years it is found in a greater variety of habitats. In Victoria Dittricha graveolens is distributed in medium to large populations in dry coastal vegetation, mallee shrubland, lowland grassland and grassy woodland, and dry sclerophyll forest and woodland. It is also found in disturbed sites in England, Germany, Austria, Netherlands.

Sources of information:
United States Department of Agriculture Natural Resources Conservation Service, 2005. Plant Profile for Dittrichia graveolens (L) W.Greuter stinkwort Nesom, G.L. 2004, Asteraceae from wool mill sites in South Carolina, including New Records for North America. SIDA 21(2) 1215-1223. Victoria (Australia) Department of Primary Industries. 2005. Impact Assessment Dittrichia graveolens. Accessed online on 4/6/05 at http://www.nre.vic.gov.au/DPI/Vro/rosite.nsf/pages/_stinkwort

Section 3: Distribution

Other Published Material B Question 3.1 Ecological amplitude/Range
Refer to Worksheet C and select the one letter below that indicates the number of different ecological types that this species invades.
A. Widespread—the species invades at least three major types or at least six minor types.
B. Moderate—the species invades two major types or five minor types.
C. Limited—the species invades only one major type and two to four minor types.
D. Narrow—the species invades only one minor type.
U. Unknown.
Describe ecological amplitude, identifying date of source information and approximate date of introduction to the state, if known:
First specimen of Ditttrichia graveolens (Accession number UC1601326) collected November 1, 1984 two miles north of Alviso in Santa Clara County along railroad tracks at the upper edge of the tidal marsh by H.T. Harvey. Dittrichia graveolens is found (based upon a ID'ed specimen) in 14 counties in California. Specimens were collected and ID'ed in Santa Clara County (1984), Alameda County (1996), Contra Costa County (1996), Madera County (1997), San Joaquin County (1997), Solano County (1998), Sonoma County (1999), YoloCounty (1999), San Mateo County (2001), Marin County (2002), Sacramento County (2002), Santa Cruz County (2002), Placer County (2003), San Diego County (2003). Counties where specimens have not been seen and/or listed, but not collected and ID'ed include San Benito County (2004) Ventura County (2004), Monterey County (2005) In California Dittrichia graveolens is primarily found in disturbed or ruderal sites particularly along roads and levees, and graded sites with few plants in late summer . It has also been found on the edge of the tidal estuary, rocky outcrops, in properly grazed and overgrazed pastureland (non-native grassland), in manipulated riparian areas, intact riparian scrub-dry washes, at the edge of drying lakes, percolation ponds, and depressions. Dittrichia graveolens has been in California too short of a time to get an accurate picture of which plant communities have been or will be invaded.

Sources of information:
enter text here Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. Preston, Robert, 2005. List of Dittricha graveolens specimens and locations: unpublished document. Pinnacles Plant Checklist December 2004 National Park Service: unpublished document. Sharon Franklet Botanist, Pinnacles National Monument: Personal Communication (2005) Jepson Herbarium Dittrichia graveolens specimens Bob Case: personal communication (2005) John Beall: personal observation (2005)

Other Published Material D Question 3.2 Distribution/Peak frequency
To assess distribution, record the letter that corresponds to the highest percent infested score entered in Worksheet C for any ecological type.
Describe distribution:
enter text here Dittrichia graveolens has not reached its peak in the state. The plant will continue to expand into a wide variety of disturbed/ruderal locations in more counties throughout the state following roads and levees into more counties. There are many more parts of the state with disturbed areas/plant communities with open or sparse plant cover in late summer that Dittrichia graveolens will expand into. In addittion Dittrichia graveolens may expand further into open riparian locations, and plant communities where harsh edaphic conditions which limit plants including soils with (heavy metals-including serpentine soils and saline soils).

Sources of information:
enter text here Danish Environmental Protection Agency. 2000. Management of Contaminated Sites and Land in Central and Eastern Europe: Albania Accessed online April 4, 2005 at http://www.mst.dk/udgiv/Publications/2000/87-7909-888-6/html/kap10-eng.htm Higueras, Pablo L. University of Castilla-La-Mancha, Spain. 2003. Presentation: Almaden: Remediation techniques in the largest mercury mining district of the world. CCMS Meeting Prevention and Remediation Issues in selected Industrial Sectors Pilot Study. Bala Mare (Romania), Sept. 7-11 2003. Accessed online April 4, 2005 at http://www.cluin.org/romania/presentations/2921843.pdf Preston R. E., Dittrichia graveolens (Asteraceae) New to California weed flora. Madrono 44(2) 200-203. Bob Case: personal communication (2005) John Beall: personal observation (2005)

Worksheet A - Innate reproductive potential

Reaches reproductive maturity in 2 years or less Yes, 1 points
Dense infestations produce >1,000 viable seed per square meter Yes, 2 points
Populations of this species produce seeds every year. Yes, 1 points
Seed production sustained over 3 or more months within a population annually Unknown
Seeds remain viable in soil for three or more years Yes, 2 points
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, 1 points
Total points: 7
Total unknowns: 2
Total score: A
Scoring Criteria for Worksheet A
A. High reproductive potential (6 or more points).
B. Moderate reproductive potential (4-5 points).
C. Low reproductive potential (3 points or less and less than 3 Unknowns).
U. Unknown (3 or fewer points and 3 or more Unknowns).
Note any related traits:
Return to Table 2

Worksheet B - Arizona Ecological Types is not included here


Worksheet C - California Ecological Types
 
(sensu Holland 1986)

Major Ecological Types Minor Ecological Types Code
A means >50% of type occurrences are invaded;
B means >20% to 50%;
C means >5% to 20%;
D means present but ≤5%;
U means unknown (unable to estimate percentage of occurrences invaded)
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
chaparral
Grasslands, Vernal Pools, coastal prairie
Meadows, and other Herbvalley and foothill grasslandD. < 5%
CommunitiesGreat 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)D. < 5%
Woodlandcismontane woodland
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)  
Distribution (highest score)  
Return to Table 2

Addendum J - Jepson Regions Infested
 
Click here for a map of Jepson regions

Infested Jepson Regions:
Check the boxes to indicate the Jepson floristic provinces in which this species is found.














Addendum L - External Links & Resources

Cal-IPC Plant Profile
The Cal-IPC Plant Profile for this species.
http://www.cal-ipc.org/ip/management/plant_profiles/Dittrichia_graveolens.php
Calflora Plant Profile:
The Calflora Plant Profile for this species.
http://www.calflora.org/cgi-bin/species_query.cgi?where-calrecnum=8482
CalWeedMapper:
Load CalWeedMapper with this species already selected.
http://calweedmapper.cal-ipc.org/maps/?species=26