APHIS List of Regulated Hosts and Plants Proven or Associated with Phytophthora ramorum

Latest revision: 
March 2024

Proven Hosts Regulated forPhytophthora ramorum

Regulated plants are those adapted from other regulated lists or were added upon completion, documentation and review of traditional Koch’s postulates. Some are regulated in part (such as redwood and Douglas-fir), others are regulated in their entirety (such as tanoak and western star flower)

Scientific Name

Common Name

Abies grandis

Grand fir

Abies magnifica

Red fir

Acer circinatum

Vine maple

Acer macrophyllum*

Bigleaf maple

Acer pseudoplatanus*

Planetree maple

Adiantum aleuticum*

Western maidenhair fern

Adiantum jordanii*

California maidenhair fern

Aesculus californica*

California buckeye

Aesculus hippocastanum*

Horse-chestnut

Arbutus menziesii*

Madrone

Arbutus unedo

Strawberry tree

Arctostaphylos columbiana

Hairy manzanita

Arctostaphylos glauca

Bigberry manzanita

Arctostaphylos hooveri

Santa Lucia manzanita

Arctostaphylos manzanita*

Manzanita

Arctostaphylos montereyensis

Monterey manzanita

Arctostaphylos morroensis

Morro manzanita

Arctostaphylos pilosula

La Panza manzanita

Arctostaphylos pumila

Sandmat manzanita

Arctostaphylos silvicola

Silverleaf manzanita

Arctostaphylos viridissima

White haired manzanita

Berberis aquifolium

(≡Mahonia aquifolium)

Oregon grape

Calluna vulgaris*

Scotch heather

Camellia spp.*

Camellia – all species, hybrids and cultivars

Castanea sativa*

Sweet chestnut

Ceanothus thyrsiflorus

Blue blossom ceanothus

Chamaecyparis lawsoniana

Port Orford cedar

Chrysolepis chrysophylla

Golden chinquapin

Cinnamomum camphora*

Camphor tree

Corylus cornuta

Beaked hazelnut

Fagus sylvatica*

European beech

Frangula californica

(=Rhamnus californica)*

California coffeeberry

Frangula purshiana

(=Rhamnus purshiana)*

Cascara

Fraxinus excelsior

European ash

Gaultheria procumbens*

Eastern Teaberry

Gaultheria shallon

Salal

Griselinia littoralis*

Griselinia

Hamamelis virginiana*

Witch hazel

Heteromeles arbutifolia*

Toyon

Kalmia spp.*

Mountain laurel – all species, cultivars & hybrids

Larix × eurolepis

Hybrid larch

Larix decidua

European larch

Larix kaempferi

Japanese larch

Laurus nobilis*

Bay laurel

Lonicera hispidula*

California honeysuckle

Lophostemon confertus

Brisbane box

Loropetalum chinense

Chinese fringe flower

Magnolia × loebneri

Loebner magnolia

Magnolia doltsopa

(=Michelia doltsopa)*

Michelia

Magnolia stellata

Star magnolia

Maianthemum racemosum

(=Smilacina racemosa)*

False Soloman’s seal

Notholithocarpusdensiflorus*

Tanoak

Parrotia persica*

Persian ironwood

Phoradendron serotinum subsp. Macrophyllum

Big-leaf mistletoe

Photinia fraseri*

Red tip photinia

Pieris spp.*

Andromeda, Pieris – all species,hybrids and cultivars

Prunus laurocerasus

Cherry laurel

Pseudotsuga menziesii var. menziesi*

Douglas-fir

Also includes all other varieties and cultivars of nursery grown P. menziesii

Quercus agrifolia*

Coast live oak

Quercus cerris*

European turkey oak

Quercus chrysolepis*

Canyon live oak

Quercus falcata*

Southern red oak

Quercus ilex*

Holm oak

Quercus kelloggii*

California black oak

Quercus parvula v. shrevei*

Shreve’s oak

Also includes all other varieties and cultivars of nursery grown Q. parvula

Rhododendron spp.*

Rhododendron & Azalea – all species,hybrids and cultivars

Rosa gymnocarpa*

Wood rose

Salix caprea*

Goat willow

Sequoia sempervirens*

Coast redwood

Syringa vulgaris*

Lilac

Taxus baccata*

European yew

Trientalis latifolia*

Western starflower

Umbellularia californica*

California bay laurel, pepperwood, Oregon myrtle

Vaccinium myrtillus

Whortleberry

Vaccinium parvifolium

Red huckleberry

Vaccinium ovatum*

Evergreen huckleberry

Viburnum spp.*

Viburnum – All species, hybrids and cultivars

Vinca minor

Periwinkle

* Unprocessed wood and wood products, including firewood, logs, lumber, and bark chips or mulch of species listed are NOT regulated.

Current list: www.aphis.usda.gov/plant_health/plant_pest_info/pram/downloads/pdf_files...

Plants Associated with Phytophthora ramorum

Regulated as nursery stock.

Associated plants are those found naturally infected from which P. ramorum has been cultured and/or detected using PCR (Polymerase Chain Reaction). For each of these, traditional Koch’s postulates have not yet been completed or documented and reviewed. Though not regulated and not requiring certification under P. ramorum regulations, these plants will be inspected in nurseries and Christmas tree plantations and, if symptoms observed, held from sale pending testing.

Scientific Name

Common Name, Date
& *Source of Report

Abies alba

Silver fir ––2016

Abies concolor

White fir – Oct 051

Abies procera

Noble fir – 2016

Acer davidii

Striped bark maple – Jan 069

Acer laevigatum

Evergreen maple – Aug 053

Alnus cordata

Italian alder – 2016

Arctostaphylos glandulosa

Eastwood’s manzanita – 2017

Arctostaphylos montaraensis

Montara manzanita – 2020

Arctostaphylos pallida

Pallid manzanita – 2017

Arctostaphylos peninsularis

Peninsular manzanita – 2020

Arctostaphylos rainbowensis

Rainbow manzanita – 2020

Arctostaphylos uva–ursi

Kinnikinnick, bearberry – Jan 0710

Arctostaphylos virgata

Bolinas manzanita – 2017

Arctostaphylos viscida

Whiteleaf manzanita – 2022

Ardisia japonica

Ardisia – Jan 069

Berberis nervosa

Creeping Oregon grape – 2010

Betula pendula

Silver birch – 2010

Calycanthus occidentalis

Spicebush – May 055

Castanopsis orthacantha

Castanopsis – Aug 063

Ceanothus oliganthus

Hairy ceanothus – 2021

Cercis chinensis

Chinese redbud – 2008

Choisya ternata

Mexican orange blossom – 2013

Clintonia andrewsiana

Andrew’s clintonia bead lily – May 045

Cornus kousa x Cornus capitata

Cornus Norman Haddon – Aug 063

Cornus capitata

Bentham’s cornel – 2015

Cornus kousa

Kousa dogwood – 2012

Corylopsis spicata

Spike winter hazel – 2008

Daphniphyllum glaucescens

Distylium myricoides

Myrtle–leafed Distylium – Jul 069

Drimys winteri

Winter’s bark – July 043

Dryopteris arguta

California wood fern – May 045

Eucalytus haemastoma

Scribbly gum – Aug 063

Euonymus kiautschovicus

Spreading euonymus – Jan 069

Fothergilla major

Mountain witch alder – 2015

Fraxinus latifolia

Oregon ash – Aug 055

Garrya elliptica

Silk tassel bush – 2007

Hamamelis x intermedia
(H. mollis & H. japonica)

Hybrid witchhazel – Jan 069

Hamamelis mollis

Chinese witchhazel – Jan 053

Hydrangea seemannii

Seemann’s hydrangea – 2015

Ilex aquifolium

European holly – 2013

Ilex cornuta

Buford holly, Chinese holly – Apr 0911

Ilex latifolia

Tarajo holly – 2015

Ilex purpurea

Oriental holly – Jul 069

Illicium parviflorum

Yellow anise13

Larix occidentalis

Western larch – 2019

Leucothoe axillaris

Fetterbush, dog hobble – Jan 069

Leucothoe fontanesiana

Drooping leucothoe – Oct 033

Lithocarpus glaber

Japanese oak – 2015

Lonicera periclymenum

Common honeysuckle – 2022

Magnolia x soulangeana

Saucer magnolia – Jan 053

Magnolia × thompsoniana

hybrid magnolia – 2008

Magnolia acuminata

Cucumber tree – 2015

Magnolia cavaleriei

Magnolia delavayi

Delavay’s magnolia – 2015

Magnolia denudata

Yulan magnolia

Magnolia denudata × salicifolia

Magnolia

Magnolia ernestii
(= Michelia wilsonii)

Michelia – Jan 069

Magnolia figo

Banana shrub – 2008

Magnolia foveolata§

Magnolia grandiflora

Southern magnolia – Jan 069

Magnolia insignis

Red lotus tree – 2006

Magnolia kobus

Kobus magnolia – 2013

Magnolia liliiflora

Lily magnolia – 2013

Magnolia lotungensis

Eastern joy lotus tree

Magnolia maudiae
(= Michelia maudiae)

Smiling monkey forest tree

Magnolia salicifolia

Anise magnolia – 2013

Molinadendron sinaloense

Nerium oleander

Oleander – Jan 061

Nothofagus obliqua

Roble beech – Dec 043

Osmanthus decorus
(=Phillyrea decora;
=P. vilmoriniana)

Osmanthus – Jun 069

Osmanthus delavayi

Delavay Osmanthus, Delavay tea olive – Jan 0710

Osmanthus fragans

Sweet olive – Jun 061

Osmanthus heterophyllus

Holly olive – Jun 061

Osmorhiza berteroi

Sweet Cicely – Aug 055

Physocarpus opulifolius

Ninebark – 2008

Picea sitchensis

Sitka spruce – 2019

Pickeringia montana

Chaparral pea – 2017

Pinus ponderosa

Ponderosa Pine – 2021

Pittosporum undulatum

Victorian box – Dec 026

Polystichum munitum

Western Swordfern – 2022

Prunus lusitanica

Portuguese cherry laurel – Jan 069

Pyracantha koidzumii

Formosa firethorn – Apr 049

Quercus acuta

Japanese evergreen oak – May 063

Quercus petraea

Sessile oak – Aug 053

Quercus phillyraeoides

Ubame oak – 2016

Quercus robur

English oak – 2015

Quercus rubra

Northern red oak – Nov 038

Ribes laurifolium

Evergreen Flowering Currant – 2013

Rosa hybrida ‘Radrazz’

Knock Out rose – 2019

Rosa rugosa

Rugosa rose – Jan 069

Rosa (specific cultivars)

Royal Bonica (MEImodac),
Pink Meidiland (MEIpoque) & Pink Sevillana (MEIgeroka) – Jan 069

Rubus spectabilis

Salmonberry – Dec 024

Rubus ursinus

California blackberry – 2017

Salix babylonica

Weeping willow – 2007

Sarcococca hookeriana

Himalayan sweet box – 2015

Schima argentea

Schima wallichil

Chinese guger tree, needlewood
– Nov 063

Sorbus aucuparia

European mountain ash – 2015

Syringa meyeri

Meyer lilac – 2019

Syringa pubescens

Lilac – 2019

Taxus brevifolia

Pacific yew – May 035

Taxus x media

Yew – Jun 058

Torreya californica

California nutmeg – Aug 055

Toxicodendron diversilobum

Poison oak – Dec 024

Trachelospermum
jasminoides

Star jasmine, Confederate jasmine
– May 102 , June 101

Tsuga heterophylla

Western hemlock – 2019

Vaccinium intermedium

Vaccinium vitis–idaea

Lingonberry – 2013

Vancouveria planipetala

Redwood ivy – Aug 055

Veronica spicata Syn.
Pseudolysimachion
spicatum

Spiked speedwell – June 101

*Source of Report

1 California Department of Food and Agriculture, Sacramento, CA

2 Oregon Department of Agriculture, Salem, OR

3 Department for Environment, Food, and Rural Affairs, UK

4 Everett Hanson, Oregon State University, Corvallis, OR

5 David Rizzo, University of California – Davis, CA

6 Mateo Garbelotto, University of California – Berkeley, CA

7 Gary Chastagner, Washington State University, Puyallup, WA

8 Plant Protection Service, Wageningen, Netherlands

9 Canadian Food Inspection Agency, Ottowa, Ontario, Canada

10 Washington State Department of Agriculture, Olympia, WA

11 Molecular Diagnostics Laboratory, Beltsville, MD

12 Department of Agriculture, Fisheries and Food, Ireland

13 Alabama Department of Agriculture and Plant Industry