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

Proven Hosts Regulated for Phytophthora 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

Acer macrophyllum*

Bigleaf maple

Acer pseudoplatanus*

Planetree maple

Adiantum aleuticum*

Western maidenhair fern

Adiantum jordanii*

California maidenhair fern

Aesculus californica*

California buckeye

Aesculus hippocastanum*


Arbutus menziesii*


Arctostaphylos manzanita*


Calluna vulgaris*

Scotch heather

Camellia spp.*

Camellia – all species, hybrids and cultivars

Castanea sativa*

Sweet chestnut

Cinnamomum camphora*

Camphor tree

Fagus sylvatica*

European beech

Frangula californica

(=Rhamnus californica)*

California coffeeberry

Frangula purshiana

(=Rhamnus purshiana)*


Fraxinus excelsior

European ash

Gaultheria procumbens*

Eastern Teaberry

Griselinia littoralis*


Hamamelis virginiana*

Witch hazel

Heteromeles arbutifolia*


Kalmia spp.*

Mountain laurel – all species, cultivars & hybrids

Laurus nobilis*

Bay laurel

Lonicera hispidula*

California honeysuckle

Magnolia doltsopa

(=Michelia doltsopa)*


Maianthemum racemosum

(=Smilacina racemosa)*

False Soloman’s seal



Parrotia persica*

Persian ironwood

Photinia fraseri*

Red tip photinia

Pieris spp.*

Andromeda, Pieris – all species,
hybrids and cultivars

Pseudotsuga menziesii var. menziesi*


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*


Taxus baccata*

European yew

Trientalis latifolia*

Western starflower

Umbellularia californica*

California bay laurel, pepperwood, Oregon myrtle

Vaccinium ovatum*

Evergreen huckleberry

Viburnum spp.*

Viburnum – All species, hybrids and cultivars

* 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 concolor

White fir – Oct 051

Abies grandis

Grand fir – June 031

Abies magnifica

Red fir – Jan 067

Acer circinatum

Vine maple – Feb 065

Acer davidii

Striped bark maple – Jan 069

Acer laevigatum

Evergreen maple – Aug 053

Arbutus unedo

Strawberry tree – Dec 027

Arctostaphylos columbiana

Manzanita – Feb 065

Arctostaphylos uva-ursi

Kinnikinnick, bearberry – Jan 0710

Ardisia japonica

Ardisia – Jan 069

Calycanthus occidentalis

Spicebush – May 055

Castanopsis orthacantha

Castanopsis – Aug 063

CeanZothus thyrsiflorus

Blueblossom – Apr 065

Clintonia andrewsiana

Andrew’s clintonia bead lily – May 045

Cornus kousa x Cornus capitata

Cornus Norman Haddon – Aug 063

Corylus cornuta

California hazelnut – Dec 025

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

Fraxinus latifolia

Oregon ash – Aug 055

Gaultheria shallon

Salal, Oregon wintergreen – Jan 069

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

Hybrid witchhazel – Jan 069

Hamamelis mollis

Chinese witchhazel – Jan 053

Ilex cornuta

Buford holly, Chinese holly – Apr 0911

Ilex purpurea

Oriental holly – Jul 069

Illicium parviflorum

Yellow anise13

Larix kaempferi

Japanese larch – Aug 093 and July 1012

Leucothoe axillaris

Fetterbush, dog hobble – Jan 069

Leucothoe fontanesiana

Drooping leucothoe – Oct 033

Loropetalum chinense

Loropetalum – Jul 069

Magnolia denudata

Lily tree – Dec 103

Magnolia ernestii
(= Michelia wilsonii

Michelia – Jan 069

Magnolia grandiflora

Southern magnolia – Jan 069

Magnolia x loebneri

Loebner magnolia – Jan 053

Magnolia maudiae
(= Michelia maudiae

Michelia – Jan 069

Magnolia x soulangeana

Saucer magnolia – Jan 053

Magnolia stellata

Star magnolia – Jan 053

Mahonia nervosa

Creeping Oregon grape – May 1010

Manglietia insignis

Red lotus tree – Aug 069

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

Parakmeria lotungensis

Eastern joy lotus tree – Jul 069

Pittosporum undulatum

Victorian box – Dec 026

Prunus laurocerasus

English laurel, Cherry laurel – Jan 079

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 rubra

Northern red oak – Nov 038

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

Schima wallichil

Chinese guger tree, needlewood
– Nov 063

Taxus brevifolia

Pacific yew – May 035

Taxus x media

Yew – Jun 058

Torreya californica

California nutmeg – Aug 055

Toxicodendron diversilobum

Poison oak – Dec 024


Star jasmine, Confederate jasmine
– May 102 , June 101

Vancouveria planipetala

Redwood ivy – Aug 055

Veronica spicata Syn.

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