The Cal-IPC Inventory

The Inventory categorizes plants that threaten California's natural areas. The Inventory includes plants that currently cause damage in California (invasive plants) as well as "Watch" plants that are a high risk of becoming invasive in the future. For information about the Inventory, see "Inventory Details" below.

The Inventory represents the best available knowledge of invasive plant experts in California. Categorization is based on an assessment of ecological impacts, conducted with transparent science-based criteria and expert review. The Inventory has no regulatory authority, and should be used with full understanding of the limitations described here.


Explanation of Cal-IPC ratings

About the Inventory assessment process

History of Inventory Updates (2018-present)

Download the Inventory (CSV)

Assessed, Not on Inventory

Plants are not listed on the Inventory when our assessment finds insignificant current impact and/or insufficient risk of becoming invasive in the future to qualify as a Watch plant. See the list of plants that have been assessed and not added to the Inventory

Pending Assessment

We maintain a list of plants that need to be assessed for current invasiveness or risk of future invasiveness. We draw from this list for periodic updates to the Inventory. See the list of plants pending assessment

Problematic Natives

A handful of native species cause ecological problems where they have been moved outside their historic range in California.
See list of problematic native plants

Using the Inventory table:

  • Click a plant’s Scientific Name to see its Plant Profile page. For the plant’s assessment, click the icon in the far right column, PAF/PRE.
  • The CDFA column lists California Dept. of Food and Agriculture weed ratings (see CDFA definitions here). A checkmark in the Hort column denotes plants that are known from horticulture; the icon in the CWM column links to the CalWeedMapper page for the plant; the icon in the ID card links to a species identification card for the plant, if available (complete listing of Species ID Cards).
  • To sort the table by any column heading (except ID Card), simply click on the column heading. To list only plants from certain Jepson Regions or Habitat Types, use the filters below.
  • “Watch” species are not currently invasive in California. Assessment has found them to be a high risk for becoming invasive in the future.

Use the buttons below to choose plants to display by region, habitat, and whether the plant is designated an invasive plant or a watch plant.

Scientific nameCommon namesRatingAlertCDFAHortCWMID cardPAF/
Acacia baileyana cootamundra wattle Watch
Acacia cyclops cyclops Acacia Watch
Acacia dealbata silver wattle Moderate
Acacia longifolia Sydney golden wattle Watch
Acacia melanoxylon blackwood Acacia Limited
Acacia paradoxa kangaroothorn Watch -*
Acacia pycnantha golden wattle Watch
Acacia saligna orange wattle Watch
Acaena novae-zelandiae biddy-biddy Watch -*
Aegilops cylindrica jointed goatgrass Watch -*
Aegilops triuncialis barb goatgrass High -*
Ageratina adenophora eupatory Moderate B
Agrostis avenacea Pacific bentgrass Limited
Agrostis stolonifera creeping bent Limited
Ailanthus altissima tree-of-heaven Moderate C*
Alhagi maurorum camelthorn Moderate -*
Alopecurus pratensis meadow foxtail Watch
Alternanthera philoxeroides alligatorweed High A*
Alyssum corsicum yellowtuft Watch
Alyssum murale yellowtuft Watch
Ambrosia trifida giant ragweed Watch B*
Ammophila arenaria European beachgrass High
Anthoxanthum odoratum sweet vernal grass Limited
Araujia sericifera bladderflower Watch -*
Arctotheca calendula fertile capeweed ModerateA*
Arctotheca prostrata capeweed Moderate
Arum italicum Italian Arum Watch
Arundo donax giant reed High -*
Asparagus aethiopicus asparagus fern Watch
Asparagus asparagoides bridal creeper Moderate
Asphodelus fistulosus onion weed Moderate-*
Atriplex semibaccata Australian saltbush Moderate
Avena barbata slender oat Moderate
Avena fatua wild oats Moderate
Bassia hyssopifolia five-hook Bassia Limited
Bellardia trixago Bellardia Limited
Berberis darwinii Darwin barberry Watch
Berteroa incana hoary Alyssum Watch -*
Brachypodium distachyon annual false-brome Moderate
Brachypodium sylvaticum slender false-brome Moderate-*
Brassica nigra black mustard Moderate
Brassica rapa field mustard Limited
Brassica tournefortii Sahara mustard High C
Briza maxima big quakinggrass Limited
Bromus diandrus ripgut brome Moderate
Bromus hordeaceus soft brome Limited
Bromus japonicus Japanese brome Limited
Bromus madritensis ssp. rubens red brome High
Bromus tectorum cheatgrass High C
Buddleja davidii butterfly bush Watch
Cakile maritima European sea rocket Limited
Carduus acanthoides plumeless thistle Limited -*
Carduus nutans musk thistle Moderate -*
Carduus pycnocephalus Italian thistle Moderate -*
Carduus tenuiflorus slenderflower thistle Limited -*
Carex pendula hanging sedge Watch
Carpobrotus chilensis sea fig Moderate
Carpobrotus edulis highway iceplant High
Carrichtera annua Ward's weed ModerateA
Carthamus lanatus woolly distaff thistle High -*
Casuarina equisetifolia beach sheoak Watch
Catharanthus roseus Madagascar periwinkle Watch
Cenchrus echinatus southern sandbur Watch B*
Cenchrus longispinus mat sandbur Watch B*
Centaurea calcitrapa purple starthistle Moderate -*
Centaurea diffusa diffuse knapweed Moderate -*
Centaurea diluta North African knapweed Watch
Centaurea jacea ssp. pratensis meadow knapweed Moderate-*
Centaurea melitensis tocalote Moderate -*
Centaurea solstitialis yellow starthistle High -*
Centaurea stoebe ssp. micranthos spotted knapweed High -*
Centaurea virgata var. squarrosa squarrose knapweed Moderate -*
Cestrum parqui willow jessamine Watch
Chasmanthe floribunda African cornflag Watch
Chondrilla juncea skeleton weed Moderate -*
Chrysanthemoides monilifera ssp. monilifera boneseed ModerateA
Cirsium arvense Canada thistle Moderate -*
Cirsium vulgare bull thistle Moderate -*
Clematis vitalba old man's beard ModerateA
Colocasia esculenta taro root Moderate
Conicosia pugioniformis narrowleaf iceplant Limited
Conium maculatum poison-hemlock Moderate
Cortaderia jubata jubatagrass High -*
Cortaderia selloana pampasgrass High
Cotoneaster franchetii orange Cotoneaster Moderate
Cotoneaster lacteus milkflower Cotoneaster Moderate
Cotoneaster pannosus silverleaf Cotoneaster Moderate
Cotula coronopifolia common brassbuttons Limited
Crataegus monogyna English hawthorn Limited
Crocosmia x crocosmiiflora montbretia Limited
Crupina vulgaris common Crupina Limited A*
Cynara cardunculus artichoke thistle Moderate -*
Cynodon dactylon Bermuda grass Moderate
Cynoglossum officinale common houndstongue Moderate
Cynosurus echinatus hedgehog dogtail Moderate
Cytisus multiflorus white Spanish broom Watch
Cytisus proliferus tagasaste Watch
Cytisus scoparius Scotch broom High -*
Cytisus striatus Portuguese broom Moderate B
Dactylis glomerata orchard grass Limited
Datura inoxia pricklyburr Watch
Delairea odorata Cape-ivy High -*
Descurainia sophia tansy mustard Limited
Digitalis purpurea foxglove Limited
Dipogon lignosus Cape sweet pea Watch
Dipsacus fullonum common teasel Moderate
Dipsacus laciniatus cutleaf teasel Watch
Dipsacus sativus Fuller's teasel Moderate
Dittrichia graveolens stinkwort Moderate-*
Dittrichia viscosa false yellowhead Watch A
Echium candicans pride-of-Madeira Limited
Echium plantagineum Patterson's curse Watch A
Egeria densa Brazilian Egeria High
Ehrharta calycina purple veldtgrass High
Ehrharta erecta panic veldtgrass Moderate
Ehrharta longiflora long-flowered veldtgrass Limited
Eichhornia crassipes water hyacinth High
Elaeagnus angustifolia Russian olive Moderate
Elymus caput-medusae medusahead High -*
Emex spinosa devil's thorn Moderate
Erica lusitanica Spanish heath Limited B
Erodium cicutarium redstem filaree Limited
Eucalyptus camaldulensis red gum Limited
Eucalyptus cladocalyx sugargum Watch
Eucalyptus globulus blue gum Limited
Euphorbia lathyris caper spurge Watch
Euphorbia myrsinites myrtle spurge Watch A
Euphorbia oblongata eggleaf spurge Limited -*
Euphorbia terracina carnation spurge Limited -*
Euphorbia virgata leafy spurge High -*
Fallopia ×bohemica Bohemian knotweed Watch A
Fallopia japonica Japanese knotweed ModerateA*
Fallopia sachalinensis giant knotweed ModerateA*
Festuca arundinacea reed fescue Moderate
Festuca myuros rat-tail fescue Moderate
Festuca perennis Italian ryegrass Moderate
Ficus carica edible fig Moderate
Foeniculum vulgare fennel Moderate
Galega officinalis professorweed Watch A*
Gazania linearis Gazania Moderate
Genista linifolia Mediterranean broom Watch
Genista monosperma bridal veil broom Moderate-*
Genista monspessulana French broom High C*
Geranium dissectum cutleaf Geranium Limited
Geranium lucidum shining Geranium Watch A
Geranium purpureum little robin Limited
Glebionis coronaria garland Chrysanthemum Limited
Glyceria declinata mannagrass Moderate
Grevillea robusta silkoak Watch
Gunnera tinctoria Chilean Gunnera Watch
Gypsophila paniculata baby's breath Watch B
Halogeton glomeratus Halogeton Moderate B*
Hedera canariensis Algerian ivy High
Hedera helix English ivy High
Helianthus tuberosus Jerusalem artichoke Watch
Helichrysum petiolare licorice plant Limited
Heliotropium amplexicaule clasping heliotrope Watch
Helminthotheca echioides bristly ox-tongue Limited
Heracleum mantegazzianum giant hogweed Watch A
Hieracium aurantiacum orange hawkweed Watch B
Hirschfeldia incana short-pod mustard Moderate
Holcus lanatus common velvet grass Moderate
Hordeum marinum Mediterranean barley Moderate
Hordeum murinum hare barley Moderate
Hydrilla verticillata Hydrilla High A*
Hyparrhenia hirta Tambookie grass Watch
Hypericum androsaemum sweet-amber Watch
Hypericum canariense Canary Island St. Johnswort ModerateB*
Hypericum grandifolium large-leaved Hypericum Watch
Hypericum perforatum St. John's wort Limited C*
Hypochaeris glabra smooth cat's-ear Limited
Hypochaeris radicata rough cat's-ear Moderate
Ilex aquifolium English holly Limited
Ipomoea indica blue morning glory Watch
Iris pseudacorus yellowflag Iris Limited B
Isatis tinctoria dyer's woad Moderate -*
Kniphofia uvaria redhot poker Watch
Kochia scoparia Kochia Limited
Lantana camara Lantana Watch
Lathyrus latifolius perennial sweet pea Watch
Lepidium chalepense lens-podded hoary cress Moderate-*
Lepidium draba heart-podded hoary cress Moderate -*
Lepidium latifolium perennial pepperweed High -*
Leptospermum laevigatum Australian tea tree Watch
Leucanthemum vulgare ox-eye daisy Moderate
Ligustrum lucidum glossy privet Limited
Limnobium spongia South American spongeplant High -*
Limonium duriusculum European sea lavender Moderate B
Limonium ramosissimum Algerian sea lavender Limited B
Linaria dalmatica ssp. dalmatica Dalmatian toadflax Moderate -*
Linaria vulgaris yellow toadflax Moderate
Lobularia maritima sweet Alyssum Limited
Ludwigia hexapetala creeping waterprimrose High C*
Ludwigia peploides floating water primrose High
Lythrum hyssopifolium hyssop loosestrife Moderate
Lythrum junceum creeping loosestrife Watch
Lythrum salicaria purple loosestrife High -*
Malephora crocea coppery Mesembryanthemum Watch
Marrubium vulgare horehound Limited
Maytenus boaria mayten Watch
Medicago polymorpha California burclover Limited
Melinis repens Natal grass Watch
Mentha pulegium pennyroyal Moderate
Mesembryanthemum crystallinum crystalline iceplant Moderate
Mesembryanthemum nodiflorum slenderleaf iceplant Limited
Myoporum laetum ngaio tree Moderate
Myosotis latifolia common forget-me-not Limited
Myriophyllum aquaticum parrotfeather High C
Myriophyllum spicatum spike watermilfoil High
Nardus stricta matgrass Watch
Nicotiana glauca tree tobacco Moderate
Nothoscordum gracile false garlic Watch -*
Olea europaea olive Limited
Oncosiphon pilulifer stinknet High Q
Ononis alopecuroides foxtail restharrow Limited -*
Onopordum acanthium Scotch thistle High -*
Onopordum illyricum Illyerian thistle Watch -*
Orobanche aegyptiaca Egyptian broomrape Watch A
Oxalis pes-caprae Bermuda buttercup Moderate
Paraserianthes lophantha plume Acacia Watch
Parentucellia viscosa yellow glandweed Limited
Parthenium hysterophorus Santa Maria feverfew Watch A*
Paspalum urvillei Vasey's grass Watch
Paspalum vaginatum seashore Paspalum Watch
Passiflora tarminiana banana passionfruit Watch
Peganum harmala African-rue Watch -*
Pennisetum clandestinum Kikuyu grass Limited C*
Pennisetum setaceum crimson fountain grass Moderate
Pennisetum villosum feathertop Watch
Persicaria wallichii Himalayan knotweed Watch -*
Phalaris aquatica harding grass Moderate
Phoenix canariensis Canary Island date palm Limited
Phytolacca americana common pokeweed Limited
Pittosporum undulatum Victorian box Watch
Plantago lanceolata English plantain Limited
Plecostachys serpyllifolia petite-licorice Watch
Poa pratensis Kentucky bluegrass Limited
Polygala myrtifolia myrtle-leaf milkwort Watch
Polypogon monspeliensis rabbitsfoot grass Limited
Potamogeton crispus curly-leaved pondweed Moderate
Potentilla recta sulphur cinquefoil Watch -*
Prunus cerasifera cherry plum Limited
Pyracantha angustifolia narrowleaf firethorn Limited
Pyracantha coccinea scarlet firethorn Limited
Pyracantha crenulata Nepalese firethorn Limited
Pyrus calleryana Callery pear Watch
Ranunculus repens creeping buttercup Limited
Raphanus sativus wild radish Limited
Rhamnus alaternus Italian buckthorn Watch
Rhaponticum repens Russian knapweed Moderate B*
Ricinus communis castor bean Limited
Robinia pseudoacacia black locust Limited
Romulea rosea var. australis rosy sandcrocus Watch
Rubus armeniacus Himalayan blackberry High
Rumex acetosella sheep sorrel Moderate
Rumex crispus curly dock Limited
Rytidosperma caespitosum wallabygrass Watch
Rytidosperma penicillatum hairy wallaby grass Limited
Saccharum ravennae ravennagrass ModerateB*
Salpichroa origanifolia lily of the valley vine Watch C
Salsola paulsenii barbwire Russian thistle Limited -*
Salsola ryanii Ryan's Russian thistle Watch
Salsola soda glasswort Moderate
Salsola tragus Russian thistle Limited C*
Salvia aethiopis Mediterranean sage Limited -*
Salvinia molesta giant Alvinia High -*
Saponaria officinalis bouncing-bet Limited
Scabiosa atropurpurea pincushion flower Watch
Schinus molle Peruvian pepper tree Limited
Schinus terebinthifolius Brazilian pepper tree Moderate
Schismus arabicus Mediterranean grass Limited
Schismus barbatus common Mediterranean grass Limited
Scolymus hispanicus goldenthistle Watch -*
Senecio elegans redpurple ragwort Watch
Senecio glomeratus cutleaf burnweed Moderate
Senecio jacobaea tansy ragwort Limited -*
Senecio linearifolius fireweed groundsel Watch -*
Sesbania punicea scarlet wisteria High -*
Silybum marianum milk thistle Limited
Sinapis arvensis wild mustard Limited
Sisymbrium irio London rocket Limited
Solanum aviculare New Zealand nightshade Watch
Solanum carolinense Carolina horsenettle Watch -*
Spartina alterniflora x S. foliosa smooth hybrid cordgrass High -*
Spartina anglica English cordgrass Moderate-*
Spartina densiflora dense-flowered cordgrass High -*
Spartina patens salt marsh hay Limited -*
Spartium junceum Spanish broom High -*
Sphaerophysa salsula alkali swainsonpea Watch -*
Stipa brachychaeta punagrass Watch -*
Stipa capensis Cape ricegrass Moderate
Stipa manicata Andean tussockgrass Limited
Stipa miliacea var. miliacea smilo grass Limited
Stipa tenuissima Mexican feathergrass Watch
Tamarix aphylla athel Limited B
Tamarix chinensis Chinese tamarisk High -*
Tamarix gallica French tamarisk High -*
Tamarix parviflora smallflower tamarisk High -*
Tamarix ramosissima saltcedar High -*
Tanacetum vulgare common tansy Moderate
Tetragonia tetragonioides New Zealand spinach Limited
Thinopyrum junceiforme Russian wheatgrass Watch
Torilis arvensis hedgeparsley Moderate
Triadica sebifera Chinese tallow tree Moderate
Tribulus terrestris puncture vine Limited -*
Trifolium hirtum rose clover Limited
Ulex europaeus gorse High -*
Undaria pinnatifida wakame Limited
Ventenata dubia North Africa grass Watch
Verbascum thapsus woolly mullein Limited
Verbena bonariensis tall vervain Watch
Vinca major periwinkle Moderate
Volutaria tubuliflora desert knapweed LimitedA*
Washingtonia robusta Mexican fan palm Moderate
Watsonia meriana bulbil Watsonia Limited
Zantedeschia aethiopica calla lily Limited
Zostera japonica dwarf eelgrass Moderate-*
Zygophyllum fabago Syrian beancaper Watch -*