Oplopanax horridus

     AK  ID  MI  MT  OR  WA  BC  ON  YT

Devil's-club is distributed from south-central Alaska south along the
Pacific Coast and the western slope of the Cascade Range to southern
Oregon and east to southwestern Yukon Territory, Idaho, and western
Montana.  Disjunct populations occur on several islands of northern Lake
Superior, including Isle Royale and Passage Island, Michigan, and
Porphyry and Slate islands, Ontario [30,45,46].  Some authorities [23]
extend its distribution to eastern Asia.  Voss [46], however, recognized
the Asian plants as a distinct species, Oplopanax elatus (Nakai) Nakai.

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This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

    1  Northern Pacific Border
    2  Cascade Mountains
    5  Columbia Plateau
    8  Northern Rocky Mountains

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Oplopanax horridus is concentrated in the Pacific Northwest, western Canada, and Alaska. It also occurs disjunctly in Michigan and Ontario, where it is considered rare.

Oplopanax horridus Torrey & A. Gray ex Miquel:
Canada (North America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Oplopanax horridus (Sm.) Miq.:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Devil's-club is a native, erect to slightly spreading, deciduous shrub
from 3.3 to 10 feet (1-3 m) in height.  It is sparsely branched with
sharp, dense prickles on stems and prominent leaf veins [24,30,48].  The
fruit is a drupe with two to three seeds [23,48].  Cooper and others
[11] noted that this species is rhizotomous; other researchers have yet
to confirm this.  Devil's-club is drought intolerant [10].

This is the only North American Oplopanax species.

Devil's-club is a wet-site indicator [38].  It grows on moderately
well-drained to poorly drained, shaded sites.  It is commonly found near
springs and streams and in drainage, seepage, and wet bottom areas
[5,8,27].  It occurs on variable aspects [9], growing in soils that are
sandy, loamy, or silty in texture.  Devil's-club-supporting soils are
sometimes skeletal.  Soils are derived from quartzite or from fluvial,
colluvial, glaciolacustrine, or morainal deposits [11,6,27].  Soil pH is
acid.  It ranges from 4.5 to 6.0 in the western redcedar/devil's-club
type of northern Idaho [11], and was measured at 3.8 in the Sitka alder
(Alnus viridis spp. sinuata)/devil's-club type of southern Alaska [39].
Soil nutrient levels are medium to very rich [24].  Climate varies from
maritime, submarine, and continental types [24].  Elevational ranges for
devil's-club in several locations are as follows:

                             feet             meters

northwestern Montana     3,900-5,000     1,189-1,524 [8]
Oregon                   1,300-4,600       396-1,402 [9,25]
northern Idaho           1,500-4,900       460-1,495 [11]
southeastern Alaska          0-1,700         0-  518 [14,47]

More info for the terms: association, selection, taiga, tree

Devil's-club is a dominant component of understories of various Pacific
Northwest and western boreal forests where moist to wet soil conditions
prevail.  Devil's-club is an indicator of numerous habitat types; some
commonly occurring ones are western redcedar (Thuja plicata)/devil's
club, western hemlock (Tsuga heterophylla)/devil's-club, Sitka spruce
(Picea sitchensis)-western hemlock/devil's-club, subalpine fir (Abies
lasiocarpa)/devil's-club, and Pacific silver fir (A. amabilis)/devil's
club [2,3,8,9].  Understories of various forest/devil's-club types are
sometimes nearly pure, dense stands of devil's-club.  Other understories
dominated by devil's-club, however, are species rich, involving mixed
shrub, shrub-fern, or shrub-forb associations [21,27].

A comprehensive list of publications naming devil's-club as a dominant
or indicator species would be prohibitively long.  A geographically
representative selection of such publications is listed below:

Old-growth forests of the Canadian Rocky Mountain national parks [1]
Forest types of the North Cascades National Park Service Complex [2]
Classification and management of riparian and wetland sites in
   northwestern Montana [8]
Plant associations and management guide for the Pacific silver fir zone
   and Gifford Pinchot National Forest [9]
Forest habitat types of northern Idaho: a second approximation [11]
Preliminary forest plant association management guide: Ketchikan Area,
   Tongass National Forest [14]
Classification, description, and dynamics of plant communities after
   fire in the taiga of interior Alaska [19]

Devil's-club tree associates not previously mentioned include noble fir
(Abies procera), grand fir (A. grandis), Alaska-cedar (Chamaecyparis
nootkatensis), Douglas-fir (Pseudotsuga menziesii), western white pine
(Pinus monticola), lodgepole pine (P. contorta varieties latifolia and
murrayana), shore pine (P. c. var. contorta), bigleaf maple (Acer
macrophyllum), quaking aspen (Populus tremuloides), and black cottonwood
(P. trichocarpa) [12,15,38,39].

Shrub associates are Alaska blueberry (Vaccinium alaskaense), ovalleaf
huckleberry (V. ovalifolium), evergreen huckleberry (V. ovatum), bog
blueberry (V. uliginosum), salmonberry (Rubus spectabilis), Rocky
Mountain maple (Acer circinatum), red-osier dogwood (Cornus sericea),
prickly currant (Ribes lacustre), and Oregon-grape (Mahonia nervosa)
[14,15,19,38].

Herbaceous associates of devil's-club include queencup beadlily
(Clintonia uniflora), trefoil foamflower (Tiarella trifoliata), starry
false-Solomon's-seal (Smilacina stellata), northern bedstraw (Galium
boreale), softleaved sedge (Carex disperma), woolly sedge (C.
laeviculmis), and coast sedge (C. obnupta) [8,38].  Other common
associates are wood horsetail (Equistum sylvaticum), ladyfern (Athyrium
filixfemina), oak-fern (Gymnocarpium dryopteris), mountain woodfern
(Dryopteris austriaca), and mosses (Mnium spp.) [8,15,27,38].

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

   FRES23  Fir - spruce
   FRES24  Hemlock - Sitka spruce
   FRES28  Western hardwoods

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

   201  White spruce
   202  White spruce - paper birch
   203  Balsam poplar
   205  Mountain hemlock
   206  Engelmann spruce - subalpine fir
   221  Red alder
   223  Sitka spruce
   224  Western hemlock
   225  Western hemlock - Sitka spruce
   226  Coastal true fir - hemlock
   227  Western redcedar - western hemlock
   228  Western redcedar
   252  Paper birch

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

   K001  Spruce - cedar - hemlock forest
   K002  Cedar - hemlock - Douglas-fir forest
   K004  Fir - hemlock forest
   K025  Alder - ash forest

Comments: Oplopanax horridus is a late seral, climax and old-growth forest understory species (Vance et al. in press). A study in southeastern Alaska showed significantly more O. horridus growing in old growth riparian than upland hardwood forests (Hanley and Hoel 1996). O. horridus can be considered an indicator species for wetlands as it grows near springs and streams and in drainage, seepage, and wet bottom areas (Minore 1983) in sandy, loamy, or silty soils (Howard 1993).

More info for the term: prescribed fire

Hamilton's Research Papers (Hamilton 2006a, Hamilton 2006b) provide
information on prescribed fire and postfire response of plant species,
including devil's-club, that was not available when this species review
was originally written.

More info for the terms: fire intensity, frequency

Postfire recovery of understory species, presumably including devil's
club, in forest/devil's-club types of British Columbia is more rapid
than in other forest types.  Researchers credit this to the generally
lower fire intensity.  Devil's-club frequency at widely scattered sites
in British Columbia that had burned less than 10 years prior to sampling
was from 61 to 80 percent [27].

Extrapolating from Alaback's [3] data (see Successional Status), devil's
club is probably absent from burn sites for decades following
stand-replacing fire.  Presumably, devil's-club establishes on these
sites from animal-dispersed seed after the canopy has closed enough to
shade this light-sensitive species.

More info for the terms: fire severity, severity

Devil's-club is susceptible to fire-kill [18], but its susceptibility by
class of fire severity is unknown.

More info for the terms: root crown, wildfire

Sites where devil's-club occurs burn infrequently.  Wildfire is uncommon
in various forest-devil's-club types of southeastern Alaska [28].
Typically, the moist ravines and streamside areas serve as a fire break
to low- and moderate-severity ground fires.  The return interval for
such fires ranges from 50 to 100 years in the western redcedar/devil's
club type of western Montana.  Less often, this type undergoes severe,
stand-replacing fire, regressing the site to pioneer conditions.
Stand-replacing fires in the western redcedar/devil's-club type of
western Montana have historically occurred at intervals ranging from 150
to more than 500 years [13].

Devil's-club adaptations to fire are not well documented.  It may sprout
from the root crown [18,42].  Sprouting from rhizomes may also occur [11].

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More info for the term: climax

Devil's-club is moderately shade tolerant [24] and is primarily found in
understories of late seral, climax, and old-growth forests.  Best growth
is attained in climax (mature) forests [6,8].  Average devil's-club
biomass at widely located sites in western hemlock-western redcedar and
Sitka spruce-western hemlock forests of southeastern Alaska was as
follows [3]:

clearcut sites:                 0.00 lb/acre
young (30- to 100-year-old):    0.09 lb/acre  (0.1 kg/ha)
mature (100- to 250-year old):  4.80 lb/acre  (5.4 kg/ha)
old-growth (250+ years):        2.90 lb/acre  (3.3 kg/ha)

More info for the terms: layering, root crown

Information on devil's-club regeneration is scant.  Seedling growth is
apparently slow [34].  Devil's-club reproduces vegetatively, but the
method is uncertain.  Vegetative reproduction may be accomplished by
rhizomes [11] and/or layering [34].  Stickney [42] tentatively listed it
as a root crown sprouter.

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More info for the term: phanerophyte

  
   Phanerophyte

More info for the term: shrub

Shrub

Overall fire potential is rated as low in western redcedar/devil's-club
habitat types of western Montana [17].

This species is browsed by deer and elk and provides shade cover for salminoids and other fishes (Vance et al. in press). It tends to grow in relatively "damaged" ecosystems (Vance et al. in press).

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Devil's-club flowers in late spring to midsummer, depending upon
location.  Plants in southeastern Alaska bloom in June [45], while
plants on the Lake Superior islands bloom in mid-July.  Fruits ripen
approximately 4 weeks after flowering and persist over winter [46].
Leaves are dropped within a few days of the first fall frost.  In the
Cascade Range of Oregon, leaf abscission occurs in October or November
[10].

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 1
Specimens with Barcodes: 5
Species With Barcodes: 1

Canada

Rounded National Status Rank: N4 - Apparently Secure

United States

Rounded National Status Rank: N4 - Apparently Secure

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Oplopanax horridus occurs from southern Oregon north through western Canada into Alaska. It also occurs disjunctly in Michigan and Ontario. It is relatively more abundant in the northern portion of its range, is considered a wetland habitat indicator, and grows in old growth riparian habitats. Although this species seems able to adapt to disturbance to a certain extent, it is threatened by high intensity fires, habitat loss, and over-grazing. This species is also potentially threatened by wild-collection for medicinal use. Interest in Oplopanax horridus for this purpose is reportedly increasing and it is closely related to other highly traded species, for which it has been used as a substitute.

Comments: Ecological threats to this species include habitat loss and fire. Habitat loss due to logging will threaten native populations, since this plant is very light sensitive (pers. comm. A. Bentley, October 2000, Alaback 1980). High intensity fires can devastate this species, however such fires may not be very frequent in its range, particularly to the north. Fire has been shown to kill populations that may take decades to regenerate by seed (Alaback 1980, Vance et al. in press). This species is also vulnerable to over-browsing by elk in limited areas.

Another potential threat is that cuttings of Oplopanax horridus collected from the wild appear to be gaining in popularity from the perspective of experienced herbalists (pers. comm. R. Klein, October 2000; pers. comm. A. Bentley, October 2000). Some experts in the medicinal plant industry have suggested that trade is medium to large and demand has increased over the past ten years (Robbins 1999). Specifically, O. horridus is gaining popularity for use as a supplement for controlling diabetes (pers. comm. A. Bentley, October 2000, Vance et al. in press). This species is also sold as "industrial grade Panax ginseng" (Vance et al. in press). Since it is possible to cultivate this plant and seeds and plants are commercially available (Vance et al. in press), it is unclear whether cultivation is relieving pressure on wild plants. Therefore, amounts of cultivated versus wild-harvested material in commercial trade should be investigated. This plant is also commercially available as an ornamental. Vance et al. (in press) suggested that utilizing specific harvesting techniques for sustainable use could alleviate long-term threats to wild populations. Therefore, potential threats caused by wild collecting can be mediated by individual collectors (see Vance et al. in press).

Comments: Many parts of this plant can be utilized for medicinal purposes, including the root, berries, stems, and leaves. Therefore, the method of harvesting can have different effects on local populations; threats associated with harvesting can be mediated according to the method used by the collector.