Source: California Invasive Plant Council
URL of this page: http://www.cal-ipc.org/ip/inventory/weedlist.php
California Invasive Plant Inventory Database
Before looking at this database, please read the information on the Invasive Plant Inventory, including how plants were listed and what the ratings mean.
Download Cal-IPC's Watchlist of plants that are not yet on the Inventory but are starting to invade wildlands: Excel spreadsheet or pdf. Last updated December 2011.
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Filter plants by region:Selecting a floristic province will show only plants found in all regions of that province, not those found in only one or a few regions. Select an individual region to see all plants found there.
> See abbreviation and scores key
> Read how the Inventory was compiled.
Click on column heading to sort the table. Click on the scientific name for the Plant Assessment Form, or the 
icon for the Plant Profile. You can also download a tab-delimited file of this data which can be imported into Microsoft Excel or other programs.
| Scientific Name | Common Name | Rating | Alert | Imp. | Inv. | Dis. | Doc. | Regions | Habitats of Concern and Comments |
|---|---|---|---|---|---|---|---|---|---|
| Acacia dealbata [View PAF] | Silver wattle | 2Moderate | B | B | B | 2.5 |
|
Coastal prairie, riparian woodland, riparian forest, North Coast coniferous forest, closed cone coniferous forest. | |
| Acacia melanoxylon [View PAF] | Black acacia, blackwood acacia | 3Limited | C | C | B | 2.7 |
|
Coniferous forest, chaparral, woodland, riparian. Impacts are low in most areas. | |
| Acroptilon repens [View PAF] | Russian knapweed | 2Moderate | B | B | B | 3.2 |
|
Scrub, grasslands, riparian, pinyon-juniper woodland, forest. Severe impacts in other western states. Spreading in many areas of CA. | |
| Aegilops triuncialis [View PAF] | Barb goatgrass | 1High | A | A | B | 3.6 |
|
Grassland, oak woodland; spreading in NW and in Central Valley. | |
| Ageratina adenophora [View PAF] | Croftonweed, eupatorium | 2Moderate | B | B | B | 2.8 |
|
Coastal canyons, scrub, slopes. Very invasive in Australia, limited information and distribution in CA. | |
| Agrostis avenacea [View PAF] | Pacific bentgrass | 3Limited | C | C | C | 2.4 |
|
Vernal pools, coastal prairie, meadows, grasslands. Impacts are low in most areas. | |
| Agrostis stolonifera [View PAF] | Creeping bentgrass | 3Limited | C | B | C | 1.9 |
|
Wetlands, riparian; grown for domestic forage. Limited distribution and impacts unknown. | |
| Ailanthus altissima [View PAF] | Tree-of-heaven | 2Moderate | B | B | B | 3.0 |
|
Riparian areas, grasslands, oak woodland. Impacts highest in riparian areas. | |
| Alhagi maurorum [View PAF] | Camelthorn | 2Moderate | B | B | B | 3.2 |
|
Grassland, meadows, riparian and desert scrub, Sonoran thorn woodland. Very invasive in southwestern states. Limited distribution in CA. | |
| Alternanthera philoxeroides [View PAF] | Alligator weed | 1High | Alert |
A | B | C | 2.9 |
|
Freshwater aquatic systems, including marshes |
| Ammophila arenaria [View PAF] | European beachgrass | 1High | A | B | B | 3.2 |
|
Coastal dunes | |
| Anthoxanthum odoratum [View PAF] | Sweet vernalgrass | 2Moderate | B | B | B | 2.7 |
|
Coastal prairie, coniferous forest. Little information available on impacts and limited ecological range. | |
| Arctotheca calendula (fertile) [View PAF] | Fertile capeweed | 2Moderate | Alert |
B | B | C | 3.6 |
|
Coastal prairie; can produce seed. Important agricultural weed in Australia, but limited distribution in CA. |
| Arctotheca calendula (sterile) [View PAF] | Sterile capeweed (synonym of Arctotheca prostrata) | 2Moderate | B | B | B | 2.8 |
|
Coastal prairie; only propagates vegetatively. More competitive than fertile form, but limited distribution. | |
| Arundo donax [View PAF] | Giant reed | 1High | A | B | A | 2.8 |
|
Riparian areas, commercially grown for musical instrument reeds, structural material, etc. | |
| Asparagus asparagoides [View PAF] | Bridal creeper | 2Moderate | Alert |
B | B | D | 2.6 |
|
Riparian woodland |
| Asphodelus fistulosus [View PAF] | Onionweed | 2Moderate | Alert |
B | A | C | 2.9 |
|
Coastal dunes, prairie, grasslands. More invasive in Australia. High invasiveness but limited distribution in CA. |
| Atriplex semibaccata [View PAF] | Australian saltbush | 2Moderate | B | B | B | 2.9 |
|
Coastal grasslands, scrub, upper salt marsh. Limited distribution, but can be very invasive regionally. | |
| Avena barbata [View PAF] | Slender wild oat | 2Moderate | B | B | A | 3.5 |
|
Coastal scrub, grasslands, oak woodland, forest. Very widespread, but impacts more severe in desert regions. | |
| Avena fatua [View PAF] | Wild oat | 2Moderate | B | B | A | 3.2 |
|
Coastal scrub, chaparral, grasslands, woodland, forest. Very widespread, but impacts more severe in desert regions. | |
| Bassia hyssopifolia [View PAF] | Fivehook bassia | 3Limited | C | C | B | 2.7 |
|
Alkaline habitats. Weed of agriculture or disturbed sites. Impacts minor in wildlands. | |
| Bellardia trixago [View PAF] | Bellardia | 3Limited | C | C | C | 1.9 |
|
Grasslands, including serpentine. Impacts and invasiveness appear to be minor. | |
| Brachypodium distachyon [View PAF] | Annual false-brome, false brome, purple false broom, stiff brome | 2Moderate | B | B | B | 2.6 |
|
Valley and foothill grassland, cimontane woodland | |
| Brachypodium sylvaticum [View PAF] | Perennial false-brome | 2Moderate | Alert |
B | A | D | 2.5 |
|
Redwoods and mixed evergreen forest in Santa Cruz Mtns. Expanding range rapidly in OR, potentially very invasive. |
| Brassica nigra [View PAF] | Black mustard | 2Moderate | B | B | A | 2.0 |
|
Widespread. Primarily a weed of disturbed sites, but can be locally a more significant problem in wildlands. | |
| Brassica rapa [View PAF] | Birdsrape mustard, field mustard | 3Limited | C | B | B | 1.8 |
|
Coastal scrub, grasslands meadows, riparian. Primarily in disturbed areas, Impacts appear to be minor or unknown in wildlands. | |
| Brassica tournefortii [View PAF] | Saharan mustard, African mustard | 1High | A | A | B | 2.3 |
|
Desert dunes, desert and coastal scrub | |
| Briza maxima [View PAF] | Big quackingrass, rattlesnakegrass | 3Limited | B | C | B | 2.3 |
|
Grasslands. Widespread in coast range. Impacts generally minor, but locally can be higher. | |
| Bromus diandrus [View PAF] | Ripgut brome | 2Moderate | B | B | A | 3.3 |
|
Dunes, scrub, grassland, woodland, forest. Very widespread, but monotypic stands uncommon. | |
| Bromus hordeaceus [View PAF] | Soft brome | 3Limited | B | C | A | 2.8 |
|
Grasslands, sagebrush, serpentine soils, many other habitats. Very widespread, but primarily in converted annual grasslands. | |
| Bromus japonicus [View PAF] | Japanese brome, Japanese chess | 3Limited | B | C | B | 2.6 |
|
Great Basin grassland, valley and foothill grassland, pinon and juniper woodland, lower montane coniferous forest | |
| Bromus madritensis ssp. rubens [View PAF] | Red brome | 1High | A | B | A | 3.0 |
|
Scrub, grassland, desert washes, woodlands | |
| Bromus tectorum [View PAF] | Downy brome, cheatgrass | 1High | A | B | A | 3.1 |
|
Interior scrub, woodlands, grasslands, pinon/Joshua tree woodland, chaparral. | |
| Cakile maritima [View PAF] | European sea-rocket | 3Limited | C | B | B | 3.6 |
|
Coastal dunes. Widespread, but impacts appear to be minor. | |
| Cardaria chalepensis [View PAF] | Lens-podded white-top | 2Moderate | Alert |
B | B | C | 3.2 |
|
Central Valley wetlands. Limited distribution in CA. May not be as invasive as C. draba. |
| Cardaria draba [View PAF] | Hoary cress | 2Moderate | B | B | B | 2.6 |
|
Riparian areas, marshes of central coast. More severe invasive in northern CA. | |
| Cardaria pubescens [View PAF] | Hairy whitetop | 3Limited | C | B | C | 2.5 |
|
Grasslands and meadows. Impacts unknown but may be significant in meadows of CaR. | |
| Carduus acanthoides [View PAF] | Plumeless thistle | 3Limited | B | C | C | 3.0 |
|
Valley and foothill grasslands. Distribution limited in CA, impacts higher locally. | |
| Carduus nutans [View PAF] | Musk thistle | 2Moderate | B | B | B | 3.1 |
|
Grasslands. More invasive in other western states. Limited distribution in CA. | |
| Carduus pycnocephalus [View PAF] | Italian thistle | 2Moderate | B | B | A | 2.9 |
|
Forest, scrub, grasslands, woodland. Very widespread. Impacts may be variable regionally. | |
| Carduus tenuiflorus [View PAF] | Slenderflower thistle | 3Limited | C | C | B | 2.8 |
|
Valley and foothill grasslands. Limited distribution, Impacts appear to be minor. | |
| Carpobrotus chilensis [View PAF] | Sea-fig, iceplant | 2Moderate | B | B | A | 1.8 |
|
Coastal dunes, scrub, prairie. Little information on species, most inferred from C. edulis. | |
| Carpobrotus edulis [View PAF] | Hottentot-fig, iceplant | 1High | A | B | A | 3.3 |
|
Coastal habitats, especially dunes | |
| Carthamus lanatus [View PAF] | Woolly distaff thistle | 2Moderate | Alert |
A | B | C | 2.8 |
|
Grasslands. Expanding in coast ranges, may become more severe. Current distribution limited. |
| Centaurea calcitrapa [View PAF] | Purple starthistle | 2Moderate | B | B | B | 2.7 |
|
Grasslands. Impacts regionally variable. Distribution relatively limited. | |
| Centaurea debeauxii [View PAF] | Meadow knapweed | 2Moderate | Alert |
B | B | C | 2.7 |
|
Grasslands. Spreading rapidly in NW CA, but distribution limited elsewhere. Little known of impacts. |
| Centaurea diffusa [View PAF] | Diffuse knapweed | 2Moderate | B | B | B | 3.3 |
|
Severe impacts in other western states. Limited distribution in CA with impacts higher in some locations. | |
| Centaurea maculosa [View PAF] | Spotted knapweed | 1High | A | B | B | 3.4 |
|
Riparian, grasslands, wet meadows, forests. More widely distributed in other western states. | |
| Centaurea melitensis [View PAF] | Malta starthistle, tocalote | 2Moderate | B | B | B | 2.6 |
|
Grasslands, oak woodland; sometimes misidentified as C. solstitialis. Impacts vary regionally. | |
| Centaurea solstitialis [View PAF] | Yellow starthistle | 1High | A | B | A | 3.0 |
|
Grasslands, woodlands, occasionally riparian | |
| Centaurea virgata ssp. squarrosa [View PAF] | Squarrose knapweed | 2Moderate | B | B | B | 2.8 |
|
Scrub, grassland, pinyon-juniper woodland. Highly invasive in UT and other western states. Limited distribution in CA. | |
| Chondrilla juncea [View PAF] | Rush skeletonweed | 2Moderate | B | B | B | 3.1 |
|
Grasslands. Very invasive in other western states, but currently limited in distribution in CA. | |
| Chrysanthemum coronarium [View PAF] | Crown daisy | 2Moderate | B | B | B | 2.0 |
|
Coastal prairie, dunes, and scrub. Impacts generally low to moderate, but can vary regionally. | |
| Cirsium arvense [View PAF] | Canada thistle | 2Moderate | B | B | B | 2.8 |
|
Grasslands, riparian areas, forests. Severe impacts in other western states. Limited distribution in CA. | |
| Cirsium vulgare [View PAF] | Bull thistle | 2Moderate | B | B | B | 3.3 |
|
Riparian areas, marshes, meadows. Widespread, can be very problematic regionally. | |
| Conicosia pugioniformis [View PAF] | Narrowleaf iceplant | 3Limited | C | B | C | 2.1 |
|
Coastal dunes, scrub, grassland. Limited distribution. Impacts generally minor but can be higher locally. | |
| Conium maculatum [View PAF] | Poison-hemlock | 2Moderate | B | B | B | 2.8 |
|
Riparian woodland, grassland. Widespread in disturbed areas. Abiotic impacts unknown. Impacts can vary locally. | |
| Cordyline australis [View PAF] | Giant dracaena, New Zealand cabbage tree | 3Limited | C | C | C | 2.0 |
|
Coniferous forest. Two reports of horticultural escape into wildlands. Appears best suited to moist, cool climates. | |
| Cortaderia jubata [View PAF] | Jubatagrass | 1High | A | A | A | 3.1 |
|
Many coastal and interior habitats | |
| Cortaderia selloana [View PAF] | Pampasgrass | 1High | A | A | B | 3.2 |
|
Coastal dunes, coastal scrub, Monterey pine, riparian, grasslands, wetlands, serpentine soils. Still spreading both coastal and inland. | |
| Cotoneaster franchetii [View PAF] | Orange cotoneaster | 2Moderate | B | A | B | 2.6 |
|
Coniferous forest. Limited distribution. Abiotic impacts largely unknown. | |
| Cotoneaster lacteus [View PAF] | Parney's cotoneaster | 2Moderate | B | B | B | 2.1 |
|
Many coastal habitats, mainly a problem from SF Bay Area north along coast but also in San Diego County. Limited distribution. Abiotic impacts largely unknown. | |
| Cotoneaster pannosus [View PAF] | Silverleaf cotoneaster | 2Moderate | B | A | B | 2.5 |
|
Many coastal habitats, mainly a problem from SF Bay Area north along coast. Limited distribution. Abiotic impacts largely unknown. | |
| Cotula coronopifolia [View PAF] | Brassbuttons | 3Limited | C | C | B | 2.2 |
|
Salt and freshwater marshes. Impacts largely unknown, but appear to be minor. | |
| Crataegus monogyna [View PAF] | Hawthorn | 3Limited | C | B | C | 3.4 |
|
Riparian habitats, woodland. Limited distribution. Impacts appear to be minor. | |
| Crocosmia x crocosmiiflora [View PAF] | Montbretia | 3Limited | C | B | B | 2.6 |
|
Coastal scrub and prairie, north coast forests. Abiotic impacts unknown. Higher invasiveness in some areas. | |
| Crupina vulgaris [View PAF] | Common crupina, bearded creeper | 3Limited | B | C | B | 3.2 |
|
Forest, woodland, grassland. Distribution limited. More invasive in other western states. | |
| Cupressus macrocarpa [View PAF] | Monterey cypress | 5Native | B | B | B | 2.3 |
|
Native to Monterey area. Invades coastal prairie, desert scrub, riparian areas. | |
| Cynara cardunculus [View PAF] | Artichoke thistle | 2Moderate | B | B | B | 4.0 |
|
Coastal grasslands. Impacts more severe in southern CA where monotypic stands are more common. | |
| Cynodon dactylon [View PAF] | Bermudagrass | 2Moderate | B | B | B | 3.3 |
|
Riparian scrub in southern CA. Common landscape weed, but can be very invasive in desert washes. | |
| Cynoglossum officinale [View PAF] | Houndstongue | 2Moderate | B | B | B | 2.5 |
|
Woodland, forest, interior dunes. Abiotic impacts unknown. Limited distribution. Can have impacts in other western states. | |
| Cynosurus echinatus [View PAF] | Hedgehog dogtailgrass | 2Moderate | B | B | A | 2.5 |
|
Oak woodland, grassland. Widespread, impacts vary regionally, but typically not in monotypic stands. | |
| Cytisus scoparius [View PAF] | Scotch broom | 1High | A | B | A | 3.2 |
|
Coastal scrub, oak woodland, horticultural varieties may also be invasive. | |
| Cytisus striatus [View PAF] | Portuguese broom | 2Moderate | B | B | B | 2.7 |
|
Coastal scrub, grasslands; often confused with C. scoparius. Limited distribution. | |
| Dactylis glomerata [View PAF] | Orchardgrass | 3Limited | C | B | B | 2.9 |
|
Grasslands, broadleaved forest, woodlands; common forage species. Impacts appear to be minor. | |
| Danthonia pilosa [View PAF] | hairy wallaby grass | 3Limited | C | C | B | 1.7 |
|
coastal terrace prairie, coastal scrub, North Coast coniferous forest, valley and foothill grassland | |
| Delairea odorata [View PAF] | Cape-ivy, German-ivy | 1High | A | A | B | 3.1 |
|
Coastal, occasionally other riparian areas, common discard from gardens. | |
| Descurainia sophia [View PAF] | Flixweed, tansy mustard | 3Limited | C | B | B | 1.9 |
|
Scrub, grassland, woodland. Impacts appear to be minor, but locally more invasive in NE CA. | |
| Digitalis purpurea [View PAF] | Foxglove | 3Limited | C | B | B | 2.4 |
|
Forest, woodland. Widely escaped ornamental. Impacts largely unknown but appear to be minor. | |
| Dipsacus fullonum [View PAF] | Common teasel | 2Moderate | B | B | B | 3.8 |
|
Grasslands, seep, riparian scrub. Impacts regionally variable, forms dense stands on occasion. | |
| Dipsacus sativus [View PAF] | Fuller's teasel | 2Moderate | B | B | B | 3.8 |
|
Grasslands, seep, bogs. Impacts regionally variable, forms dense stands on occasion. | |
| Dittrichia graveolens [View PAF] | Stinkwort | 2Moderate | Alert |
B | A | C | 3.0 |
|
Grasslands, riparian scrub. Spreading rapidly, impacts may become more important in future. |
| Echium candicans [View PAF] | Pride-of-Madeira | 3Limited | C | B | B | 1.5 |
|
Little information on impacts. | |
| Egeria densa [View PAF] | Brazilian egeria | 1High | A | A | B | 3.1 |
|
Streams, ponds, sloughs, lakes, Sacramento-San Joaquin Delta. | |
| Ehrharta calycina [View PAF] | Purple veldtgrass | 1High | A | A | B | 3.4 |
|
Sandy soils, especially dunes; rapidly spreading on central coast. | |
| Ehrharta erecta [View PAF] | Erect veldtgrass | 2Moderate | B | B | B | 2.2 |
|
Scrub, grasslands, woodland, forest. Spreading rapidly, impacts may become more important in future. | |
| Ehrharta longiflora [View PAF] | Long-flowered veldtgrass | 2Moderate | Alert |
B | B | C | 2.8 |
|
Coastal scrub. Limited distribution, but spreading rapidly in southern CA. Impacts largely unknown. |
| Eichhornia crassipes [View PAF] | Water hyacinth | 1High | Alert |
A | A | C | 3.2 |
|
Aquatic systems in Sacramento-San Joaquin Delta |
| Elaeagnus angustifolia [View PAF] | Russian-olive | 2Moderate | B | A | B | 3.3 |
|
Interior riparian. Impacts more severe in other western states. Current distribution limited in CA. | |
| Emex spinosa [View PAF] | Spiny emex, devil's-thorn | 2Moderate | Alert |
B | B | D | 1.6 |
|
Edges of beaches, other coastal habitats. Invasive in other states and countries. Spreading rapidly in southern CA. Impacts not well known. |
| Erechtites glomerata, E. minima [View PAF] | Australian fireweed, Australian burnweed | 2Moderate | C | B | A | 3.2 |
|
Coastal woodland, scrub, forests. Widespread on coast, but impacts low overall. May vary locally. | |
| Erica lusitanica [View PAF] | Spanish heath, | 3Limited | C | B | C | 2.4 |
|
Disturbed open, sandy areas. Humboldt, Del Norte, Mendocino. | |
| Erodium cicutarium [View PAF] | Redstem filaree | 3Limited | C | C | A | 3.1 |
|
Many habitats. Widespread. Impacts minor in wildlands. High-density populations transient. | |
| Eucalyptus camaldulensis [View PAF] | Red gum | 3Limited | C | C | C | 2.2 |
|
Mainly southern CA urban areas. Impacts, invasiveness and distribution all minor. | |
| Eucalyptus globulus [View PAF] | Tasmanian blue gum | 2Moderate | B | B | B | 2.8 |
|
Riparian areas, coastal grasslands, scrub. Impacts can be much higher in coastal areas. | |
| Euphorbia esula [View PAF] | Leafy spurge | 1High | Alert |
A | A | C | 3.5 |
|
Forests, woodlands, juniper forest. More widespread invasive in northern states. |
| Euphorbia oblongata [View PAF] | Oblong spurge | 3Limited | C | C | B | 2.0 |
|
Meadows, woodlands. Limited distribution. Impacts unknown. Locally in dense stands. | |
| Euphorbia terracina [View PAF] | Carnation spurge | 2Moderate | Alert |
B | B | C | 1.7 |
|
Coastal scrub. Limited distribution. Spreading in southern CA. Impacts unknown. |
| Festuca arundinacea [View PAF] | Tall fescue | 2Moderate | B | B | A | 2.9 |
|
Coastal scrub, grasslands; common forage grass. Widespread, abiotic impacts unknown. | |
| Ficus carica [View PAF] | Edible fig | 2Moderate | B | A | B | 2.6 |
|
Riparian woodland. Can spread rapidly. Abiotic impacts unknown. Can be locally very problematic. | |
| Foeniculum vulgare [View PAF] | Fennel | 1High | A | B | A | 3.0 |
|
Grasslands, scrub. | |
| Gazania linearis [View PAF] | gazania | 2Moderate | Alert |
B | B | C | 2.2 |
|
riparian/wetland, coastal, coastal sage, chaparral, grassland, desert |
| Genista monspessulana [View PAF] | French broom | 1High | A | A | B | 3.2 |
|
Coastal scrub, oak woodland, grasslands. Horticultural selections may also be invasive. | |
| Geranium dissectum [View PAF] | Cutleaf geranium | 2Moderate | C | B | A | 1.7 |
|
Numerous habitats but impacts appear minor. | |
| Glyceria declinata [View PAF] | Waxy mannagrass | 2Moderate | B | B | B | 1.9 |
|
Vernal pools, moist grasslands. Often confused with native Glyceria. Impacts largely unknown, but may be significant in vernal pools. | |
| Halogeton glomeratus [View PAF] | Halogeton | 2Moderate | B | A | B | 3.0 |
|
Scrub, grasslands, pinyon-juniper woodland. Larger problem in NV. Monotypic stands are rare. | |
| Hedera helix, H. canariensis [View PAF] | English ivy, Algerian ivy | 1High | A | A | A | 2.7 |
|
Coastal forests, riparian areas. Species combined due to genetics questions. | |
| Helichrysum petiolare [View PAF] | Licoriceplant | 3Limited | C | B | C | 2.0 |
|
North coastal scrub. Limited distribution. Impacts unknown, but can form dense stands. | |
| Hirschfeldia incana [View PAF] | Shortpod mustard, summer mustard | 2Moderate | B | B | A | 1.9 |
|
Scrub, grasslands, riparian areas. Impacts not well understood, but appear to be greater in southern CA. | |
| Holcus lanatus [View PAF] | Common velvet grass | 2Moderate | B | B | A | 2.9 |
|
Coastal grasslands, wetlands. Impacts can be more severe locally, especially in wetland areas. | |
| Hordeum marinum, H. murinum [View PAF] | Mediterranean barley, hare barley, wall barley | 2Moderate | B | B | A | 2.8 |
|
Grasslands; H. marinum invades drier habitats, while H. murinum invades wetlands. Widespread, but generally do not form dominant stands. | |
| Hydrilla verticillata [View PAF] | Hydrilla | 1High | Alert |
A | B | C | 3.2 |
|
Freshwater aquatic systems. The most important submerged aquatic invasive in southern states. |
| Hypericum canariense [View PAF] | Canary Island hypericum | 2Moderate | Alert |
B | B | C | 1.2 |
|
Coastal scrub, prairie. Impacts unknown, distribution limited. Spreading rapidly on central coast. |
| Hypericum perforatum [View PAF] | Common St. John's wort, klamathweed | 2Moderate | B | B | B | 3.7 |
|
Many northern CA habitats. Abiotic impacts low. Biological control agents have reduced overall impact. | |
| Hypochaeris glabra [View PAF] | Smooth catsear | 3Limited | C | B | B | 3.1 |
|
Scrub and woodlands. Widespread. Impacts appear to be minor. Some local variability. | |
| Hypochaeris radicata [View PAF] | Rough catsear, hairy dandelion | 2Moderate | C | B | A | 2.2 |
|
Coastal dunes, scrub, and prairie; woodland, forest. Widespread. Impacts unknown or appear to be minor. | |
| Ilex aquifolium [View PAF] | English holly | 2Moderate | Alert |
B | B | C | 2.7 |
|
North coast forests. Expanding range south from OR. |
| Iris pseudacorus [View PAF] | Yellowflag iris | 3Limited | C | B | C | 2.3 |
|
Riparian, wetland areas, esp. southern CA. Limited distribution. Abiotic impacts unknown. | |
| Isatis tinctoria [View PAF] | Dyer's woad | 2Moderate | B | B | A | 3.0 |
|
Great Basin scrub and grasslands, coniferous forest. More severe impacts in other western states, but can be locally very invasive in northern CA. | |
| Kochia scoparia [View PAF] | Kochia | 2Moderate | B | C | B | 3.2 |
|
Scrub, chaparral, grasslands | |
| Lepidium latifolium [View PAF] | Perennial pepperweed, tall whitetop | 1High | A | A | A | 3.1 |
|
Coastal and inland marshes, riparian areas, wetlands, grasslands; potential to invade montane wetlands. | |
| Leucanthemum vulgare [View PAF] | Ox-eye daisy | 2Moderate | B | B | B | 2.5 |
|
Montane meadows, coastal grasslands, coastal scrub. Expanding range, invasiveness varies locally. | |
| Limnobium laevigatum [View PAF] | South American spongeplant, | 1High | Alert |
A | A | C | 3.0 |
|
Rivers, streams, Delta. Spreading rapidly. |
| Limonium ramosissimum ssp. provinciale [View PAF] | Algerian sea lavendar | 3Limited | C | C | D | 2.4 |
|
salt, brackish, or freshwater marshes | |
| Linaria genistifolia ssp. dalmatica [View PAF] | Dalmation toadflax | 2Moderate | B | B | B | 2.8 |
|
Grasslands, forest clearings. Limited distribution. More severe impacts in other western states. | |
| Linaria vulgaris [View PAF] | Yellow toadflax, butter and eggs | 2Moderate | B | B | B | 2.3 |
|
valley and foothill grassland, Great Basin grassland, riparian woodland, lower montane coniferous forest, upper montane coniferous forest | |
| Lobularia maritima [View PAF] | Sweet alyssum | 3Limited | C | B | B | 2.4 |
|
Coastal dune, coastal scrub, coastal prairie, riparian. | |
| Lolium multiflorum [View PAF] | Italian ryegrass | 2Moderate | A | B | A | 2.6 |
|
Grasslands, oak woodland, pinyon-juniper woodland; widely used for post-fire erosion control. Widespread. Impacts can vary with region. | |
| Ludwigia hexapetala [View PAF] | Uruguay water-primrose | 1High | Alert |
A | B | C | 2.6 |
|
Freshwater aquatic systems. Clarification needed on taxonomic identification. |
| Ludwigia peploides ssp. montevidensis [View PAF] | Creeping water-primrose | 1High | A | B | B | 2.5 |
|
Freshwater aquatic systems. Clarification needed on taxonomic identification. | |
| Lupinus arboreus [View PAF] | Yellow bush lupine | 5Native | B | B | B | 3.5 |
|
Invasive in NW coastal dunes. | |
| Lythrum hyssopifolium [View PAF] | Hyssop loosestrife | 3Limited | C | B | B | 3.0 |
|
Grasslands, wetlands, vernal pools. Widespread. Impacts unknown, but appear to be minor. | |
| Lythrum salicaria [View PAF] | Purple loosestrife | 1High | A | A | B | 3.8 |
|
Wetlands, marshes, riparian areas | |
| Marrubium vulgare [View PAF] | White horehound | 3Limited | C | C | B | 2.8 |
|
Grasslands scrub, riparian areas. Widespread. Rarely in dense stands. Impacts relatively minor. | |
| Medicago polymorpha [View PAF] | California burclover | 3Limited | C | C | A | 2.8 |
|
Grasslands. Widespread weed of agriculture and disturbed areas. Impacts in wildlands minor. | |
| Mentha pulegium [View PAF] | Pennyroyal | 2Moderate | C | A | A | 2.7 |
|
Vernal pools, wetlands. Poisonous to livestock. Spreading rapidly. Impacts largely unknown. | |
| Mesembryanthemum crystallinum [View PAF] | Crystalline iceplant | 2Moderate | Alert |
B | B | C | 3.7 |
|
Coastal bluffs, dunes, scrubs, grasslands. Limited distribution. Locally problematic, especially in southern CA. |
| Myoporum laetum [View PAF] | Myoporum | 2Moderate | B | B | B | 2.6 |
|
Coastal habitats, riparian areas; mostly along the southern coast. Abiotic impacts unknown. | |
| Myosotis latifolia [View PAF] | Common forget-me-not | 3Limited | C | B | B | 2.2 |
|
Coniferous forest, riparian. Little information on impacts. | |
| Myriophyllum aquaticum [View PAF] | Parrotfeather | 1High | Alert |
A | B | C | 2.8 |
|
Freshwater aquatic systems |
| Myriophyllum spicatum [View PAF] | Eurasian watermilfoil | 1High | A | A | B | 2.8 |
|
Freshwater aquatic systems | |
| Nanozostera japonica [View PAF] | dwarf eelgrass | 1High | Alert |
B | B | C | 3.2 |
|
Mudflats. Currently only in Humboldt Bay and Eel River Estuary. |
| Nassella manicata [View PAF] | tropical needlegrass, | 3Limited | C | C | C | 2.2 |
|
Coastal terrace prairie, coastal scrub | |
| Nicotiana glauca [View PAF] | Tree tobacco | 2Moderate | B | B | B | 2.5 |
|
Coastal scrub, grasslands, riparian woodland. Abiotic impacts unknown. Impacts vary locally. Rarely in dense stands. | |
| Olea europaea [View PAF] | Olive | 3Limited | C | B | B | 2.5 |
|
A problem in Australia. Currently a rare escape in CA but is of concern due to the possibility of spread from planted groves. | |
| Ononis alopecuroides [View PAF] | Foxtail restharrow | 3Limited | C | B | C | 2.2 |
|
Grasslands, oak woodland. Highly invasive. Impacts unknown. Nearly eradicated. | |
| Onopordum acanthium [View PAF] | Scotch thistle | 1High | B | B | B | 2.9 |
|
Wet meadows, sage brush, riparian areas | |
| Oxalis pes-caprae [View PAF] | Bermuda buttercup, buttercup oxalis, yellow oxalis | 2Moderate | B | B | B | 2.9 |
|
Coastal dunes, scrub, oak woodland. Impacts in coastal areas may prove more severe in time. | |
| Parentucellia viscosa [View PAF] | Yellow glandweed, sticky parentucellia | 3Limited | C | B | B | 2.5 |
|
Coastal prairie, grassland, and dunes. Impacts unknown, but can be locally significant. | |
| Pennisetum clandestinum [View PAF] | Kikuyugrass | 3Limited | C | C | B | 2.3 |
|
Present at low levels in numerous wildland habitats. Impacts unknown. Common turf weed. | |
| Pennisetum setaceum [View PAF] | Crimson fountaingrass | 2Moderate | B | B | B | 2.9 |
|
Coastal dunes and scrub, chaparral, grasslands. Some horticultural cultivars sterile. Very invasive in Hawaii. | |
| Phalaris aquatica [View PAF] | Hardinggrass | 2Moderate | B | B | B | 2.6 |
|
Coastal sites, especially moist soils. Limited distribution. Can be highly invasive locally. | |
| Phoenix canariensis [View PAF] | Canary Island date palm | 3Limited | C | B | D | 2.3 |
|
Desert washes; agricultural crop plant. Limited distribution in southern CA. Impacts can be higher locally. | |
| Phragmites australis [View PAF] | Common reed | 5Native | B | B | B | 2.5 |
|
Genetic issues make it unclear which strains are native to CA. | |
| Phytolacca americana [View PAF] | Common pokeweed | 3Limited | C | B | C | 2.8 |
|
riparian forest, riparian woodland | |
| Picris echioides [View PAF] | Bristly oxtongue | 3Limited | C | B | B | 2.4 |
|
Coastal prairie, scrub, riparian woodland. Widespread locally. Abiotic impacts unknown. | |
| Pinus radiata cultivars [View PAF] | Monterey pine | 5Native | B | B | B | 2.6 |
|
Five populations native to CA. Invades coastal scrub and prairie, chaparral. | |
| Piptatherum miliaceum [View PAF] | Smilograss | 3Limited | C | B | B | 2.4 |
|
Coastal dunes, scrub, riparian, grassland. Expanding range. Impacts largely unknown. | |
| Plantago lanceolata [View PAF] | Buckhorn plantain, English plantain | 3Limited | C | C | B | 2.1 |
|
Many habitats. Turf weed primarily. Low density and impact in wildlands. | |
| Poa pratensis [View PAF] | Kentucky bluegrass | 3Limited | C | B | B | 2.7 |
|
Grasslands scrub, riparian areas. Widespread turf plant. Abiotic impacts unknown. | |
| Polygonum cuspidatum [View PAF] | Japanese knotweed | 2Moderate | Alert |
B | B | D | 2.7 |
|
Riparian areas, wetlands, forest edges. More severe impacts in NW wetlands. Distribution limited in CA. |
| Polygonum sachalinense [View PAF] | Sakhalin knotweed | 2Moderate | Alert |
B | B | D | 2.5 |
|
Riparian areas. More severe impacts in NW wetlands. Distribution limited in CA. |
| Polypogon monspeliensis and subspp. [View PAF] | Rabbitfoot polypogon, annual beardgrass | 3Limited | C | C | B | 2.3 |
|
Margins of ponds and streams, seasonally wet places, edge of coastal dunes. Widespread. Impacts appear to be minor. | |
| Potamogeton crispus [View PAF] | Curlyleaf pondweed | 2Moderate | B | B | B | 3.2 |
|
Freshwater aquatic systems. Can be very invasive locally. | |
| Prunus cerasifera [View PAF] | Cherry plum | 3Limited | C | B | B | 1.8 |
|
Riparian habitats, chaparral, woodland. Limited distribution. Abiotic impacts unknown. | |
| Pyracantha angustifolia, P. crenulata, P. coccinea [View PAF] | Pyracantha, firethorn | 3Limited | C | B | B | 2.8 |
|
Coastal scrub and prairie, riparian areas. Horticultural escape. Impacts unknown or minor. | |
| Ranunculus repens [View PAF] | Creeping buttercup | 3Limited | C | C | B | 2.9 |
|
Riparian areas, coniferous forest. Impacts appear to be minor to negligible in most areas. | |
| Raphanus sativus [View PAF] | Radish | 3Limited | C | C | B | 2.5 |
|
Present at low levels in numerous habitats. Widespread in disturbed sites. | |
| Retama monosperma [View PAF] | Bridal broom | 2Moderate | Alert |
B | B | C | 1.8 |
|
Coastal scrub. Can spread rapidly but largely if uncontrolled. Limited distribution in CA. |
| Ricinus communis [View PAF] | Castorbean | 3Limited | C | B | B | 2.5 |
|
Coastal scrub and prairie, riparian areas. Widespread in southern CA. Impacts locally variable. | |
| Robinia pseudoacacia [View PAF] | Black locust | 3Limited | C | B | B | 2.8 |
|
Riparian areas, canyons. Severe impacts in southern states. Impacts minor in CA. | |
| Rubus armeniacus [View PAF] | Himalaya blackberry | 1High | A | A | A | 3.0 |
|
Riparian areas, marshes, oak woodlands | |
| Rumex acetosella [View PAF] | Red sorrel, sheep sorrel | 2Moderate | B | B | A | 2.3 |
|
Many habitats, riparian areas, forest, wetlands. Widespread. Abiotic impacts unknown. Impacts can vary locally. | |
| Rumex crispus [View PAF] | Curly dock | 3Limited | C | C | A | 2.7 |
|
Grasslands, vernal pool, meadows, riparian. Widespread. Impacts appear to be minor. | |
| Saccharum ravennae [View PAF] | Ravennagrass | 2Moderate | Alert |
B | A | C |
|
riparian scrub, marsh and swamp | |
| Salsola paulsenii [View PAF] | Barbwire Russian-thistle | 3Limited | C | C | C | 2.9 |
|
Desert and Great Basin scrub. Limited distribution. Impacts in desert appear to be minor. | |
| Salsola soda [View PAF] | Oppositeleaf Russian thistle | 2Moderate | B | B | B | 2.8 |
|
marine systems, estuaries, vernal pool, marsh and swamp | |
| Salsola tragus [View PAF] | Russian-thistle | 3Limited | C | B | B | 2.8 |
|
Desert dunes and scrub, alkali playa. Widespread. Impacts minor in wildlands. | |
| Salvia aethiopis [View PAF] | Mediterranean sage | 3Limited | C | B | B | 2.5 |
|
Sagebrush, juniper, bunchgrass. Distribution limited. Impacts minor but can be locally higher. | |
| Salvinia molesta [View PAF] | Giant salvinia | 1High | Alert |
A | A | C | 2.9 |
|
Freshwater aquatic systems. Population in San Diego River was eradicated. |
| Sapium sebiferum [View PAF] | Chinese tallowtree | 2Moderate | Alert |
B | B | C | 3.2 |
|
Riparian areas. Impacts severe in southeast US. Limited distribution in California, but spreading rapidly regionally. |
| Saponaria officinalis [View PAF] | Bouncingbet | 3Limited | C | B | C | 2.5 |
|
Riparian scrub and woodland. Impacts unknown or minor, but appear to be locally variable. | |
| Schinus molle [View PAF] | Peruvian peppertree | 3Limited | C | B | B | 2.5 |
|
Riparian. Limited distribution. Impacts largely unknown in CA. | |
| Schinus terebinthifolius [View PAF] | Brazilian peppertree | 3Limited | C | B | C | 2.6 |
|
Riparian. Very invasive in tropics. Abiotic impacts unknown, but appear significant locally. | |
| Schismus arabicus, Schismus barbatus [View PAF] | Mediterraneangrass | 3Limited | B | C | A | 2.3 |
|
Scrub, thorn woodland. Widespread in deserts. Impacts can be more important locally. | |
| Senecio jacobaea [View PAF] | Tansy ragwort | 3Limited | C | B | B | 2.8 |
|
Grasslands, riparian. Impacts generally minor. Can be locally important in NW CA. | |
| Sesbania punicea [View PAF] | Red sesbania, scarlet wisteria | 1High | Alert |
A | B | C | 3.2 |
|
Riparian areas |
| Silybum marianum [View PAF] | Blessed milkthistle | 3Limited | C | C | A | 3.5 |
|
Grasslands, riparian. Widespread, primarily in disturbed areas Impacts can be higher locally | |
| Sinapis arvensis [View PAF] | Wild mustard, charlock | 3Limited | C | C | C | 2.9 |
|
Grasslands. Primarily in disturbed sites. Impacts minor or unknown in wildlands. | |
| Sisymbrium irio [View PAF] | London rocket | 2Moderate | B | B | A | 1.9 |
|
Scrub, grasslands. Widespread. Primarily in disturbed sites. Impacts vary locally. | |
| Spartina alterniflora (and S. alterniflora x foliosa hybrids) [View PAF] | Smooth cordgrass and hybrids, Atlantic cordgrass | 1High | Alert |
A | A | C | 3.5 |
|
San Francisco Bay salt marshes and mudflats. Hybridizes with native S. foliosa. |
| Spartina anglica [View PAF] | Common cordgrass | 2Moderate | Alert |
B | B | D | 3.4 |
|
San Francisco Bay salt marshes. Very severe impact in other countries. Limited distribution in CA. |
| Spartina densiflora [View PAF] | Dense-flowered cordgrass | 1High | Alert |
A | B | D | 3.3 |
|
San Francisco and Humboldt Bay salt marshes |
| Spartina patens [View PAF] | Saltmeadow cord grass | 3Limited | C | C | D | 2.9 |
|
San Francisco Bay salt marshes. Very limited distribution. Impacts currently minor in CA, but high in other countries. | |
| Spartium junceum [View PAF] | Spanish broom | 1High | A | B | B | 3.2 |
|
Coastal scrub, grasslands, wetlands, oak woodland, forests | |
| Stipa capensis [View PAF] | Mediterranean steppegrass,twisted-awned speargrass | 2Moderate | Alert |
B | B | D | 1.9 |
|
Desert scrub; first recorded in CA 1995. Limited distribution, but spreading rapidly in CA deserts. |
| Taeniatherum caput-medusae [View PAF] | Medusahead | 1High | A | A | A | 3.4 |
|
Grasslands, scrub, woodland | |
| Tamarix aphylla [View PAF] | Athel tamarisk | 3Limited | C | B | B | 3.5 |
|
Desert washes, riparian areas. Limited distribution. Impacts minor, but can be locally higher. | |
| Tamarix parviflora [View PAF] | Smallflower tamarisk | 1High | A | A | B | 3.1 |
|
Riparian areas, desert washes, coastal scrub | |
| Tamarix ramosissima [View PAF] | Saltcedar, tamarisk | 1High | A | A | A | 3.3 |
|
Desert washes, riparian areas, seeps and springs | |
| Tanacetum vulgare [View PAF] | Common tansy | 2Moderate | B | B | B | 2.3 |
|
Riparian areas, forest. Limited distribution. Severe problem in other western states. | |
| Tetragonia tetragonioides [View PAF] | New Zealand spinach | 3Limited | C | C | C | 1.7 |
|
Coastal bluffs, sandy soils, intertidal zones | |
| Torilis arvensis [View PAF] | Hedgeparsley | 2Moderate | C | B | B | 2.3 |
|
Expanding range. Appear to have only moderate ecological impacts. | |
| Trifolium hirtum [View PAF] | Rose clover | 2Moderate | C | B | B | 2.8 |
|
Grasslands, oak woodland. Widely planted in CA. Impacts relatively minor in most areas. | |
| Ulex europaeus [View PAF] | Gorse | 1High | A | B | B | 2.9 |
|
Scrub, woodland, forest, coastal grassland | |
| Undaria pinnatifida [View PAF] | Wakame | 3Limited | C | B | C | 3.3 |
|
Alga of estuaries. First recorded in CA in 2000. Impacts unknown, but do not appear to be significant | |
| Verbascum thapsus [View PAF] | Common mullein,woolly mullein | 3Limited | C | B | B | 3.8 |
|
Meadows, riparian, sagebrush, pinyon-juniper woodlands. Widespread. Impacts minor. | |
| Vinca major [View PAF] | Big periwinkle | 2Moderate | B | B | B | 2.8 |
|
Riparian, oak woodlands, coastal scrub. Distribution currently limited but spreading in riparian areas. Impacts can be higher locally. | |
| Vulpia myuros [View PAF] | Rattail fescue | 2Moderate | B | B | A | 3.0 |
|
Coastal sage scrub, chaparral. Widespread. Rarely forms monotypic stands, but locally problematic | |
| Washingtonia robusta [View PAF] | Mexican fan palm | 2Moderate | Alert |
B | B | C | 2.7 |
|
Desert washes. Limited distribution but spreading in southern CA. Impacts can be higher locally. |
| Watsonia meriana [View PAF] | Bulbil watsonia | 3Limited | C | B | C | 2.3 |
|
Coastal prairie, coniferous forest. Abiotic impacts unknown, but may be locally dense. | |
| Zantedeschia aethiopica [View PAF] | Calla lily | 3Limited | C | B | C | 2.1 |
|
Coastal prairie, wetlands. Impacts high in other countries and local impacts may be high in CA. |
Column heading abbreviations:
Imp. = ImpactInv. = Invasiveness
Dis. = Distribution
Doc. = Documentation Level (Documentation level averaged)
Scores:
A = SevereB = Moderate
C = Limited
D = None
U = Unknown
Nomenclature:
Scientific names are based on The Jepson Manual.For each species, the first common name is based on the Weed Science Society of America's "Composite List of Weeds", followed by other names used in California.
Citation:
Cal-IPC. 2006. California Invasive Plant Inventory. Cal-IPC Publication 2006-02. California Invasive Plant Council: Berkeley, CA.[ top of page ]
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