Symphoricarpos albus

General: Honeysuckle family (Caprifoliaceae). Snowberry (Symphoricarpos albus) is a shrub or small tree that grows up to six meters tall. The leaves are large, opposite, divided into five to seven leaflets, and toothed or irregularly lobed. The fruits are white, berry like drupes, and one to one and a half centimeters in diameter. The flowers are small, white to creamy, with a strong unpleasant odor; numerous in a rounded or pyramidal parasol-like cluster (Pojar & MacKinnon 1994); blooming from mid May to July. The fruits are roundish, dull-white berries about 3/8 inch in diameter, soon becoming blackish, ripening August or September (Grimm 1993).

Distribution: Snowberry inhabits slopes and valley bottoms of the foothills of the Coast Ranges, the Sierra Nevada, and the mountains of southern California (McMinn 1939). It extends northward to British Columbia and eastward to Pennsylvania and the New England states (Ibid.).

For current distribution, please consult the Plant profile page for this species on the PLANTS Web site.

White coralberry, common snowberry

More info for the term: shrub

Common snowberry occurs from Hudson Bay to Alaska, south to California and east to North Carolina. Symphoricarpos albus var. albus, the Atlantic slope variety, has the same general distribution described above for common snowberry. Symphoricarpos albus var. laevigatus, Pacific slope variety, is found from southern Alaska south to California, Montana and Colorado [38,65].

Common snowberry was introduced into England in 1817 and is now well naturalized [47]. Delaware [34] lists it as an introduced species (see other status). In Utah it is classified as a cultivated ornamental shrub introduced from elsewhere in North America [116].

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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

3 Southern Pacific Border

4 Sierra Mountains

5 Columbia Plateau

6 Upper Basin and Range

8 Northern Rocky Mountains

9 Middle Rocky Mountains

10 Wyoming Basin

11 Southern Rocky Mountains

12 Colorado Plateau

13 Rocky Mountain Piedmont

14 Great Plains

15 Black Hills Uplift

16 Upper Missouri Basin and Broken Lands

AK
CA CO CT DE ID IL IN IA KS KY MD MA MI MN MT NE NH NJ NM
NY ND OH OR PA RI SD TN UT VT VA WA WV WI WY DC

AB BC MB NB NF NT NS ON PE PQ SK YK

Symphoricarpos albus (L.) S.F. Blake:
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.

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: It is distributed throughout North America with the exception of Mexico. The plant may be found associated with FESTUCA IDAHOENSIS or CRATAEGUS on north-facing slopes in the Palouse region of eastern Washington and northern Idaho (Daubenmire 1970, Allen et al. 1980). In the Blue Mountains of northeastern Oregon, S. ALBUS is found with FESTUCA IDAHOENSIS, AGROPYRON SPICATUM, POA SANDBERGII, and CAREX GEYERI in grasslands and as an element of the understory in Ponderosa pine forests (Holechek et al. 1982). S. ALBUS also occurs in Douglas fir zones of southern British Columbia (McLean 1969). Agee and Dunwiddie (1984) found S. ALBUS in two habitats on Yellow Island in Puget Sound, Washington: (1) in woodlands associated with madrone, Oregon white oak, and invading Douglas fir and (2) as an element of the understory in Douglas fir- madrone-grand fir forests. According to Munz and Keck (1968), S. ALBUS is found on banks and flats in canyons and near streams below 4,000 feet in mixed evergreen forests, foothill woodlands, yellow pine forests, etc., of the Coast Ranges of California from Monterey County north and northern Sierra Nevada to Alaska.

Symphoricarpos albus is found along stream banks, in swampy thickets, moist clearings and open forests at sea level to middle elevations (Pojar & MacKinnon 1994). It tolerates soil types but grows best in heavy clay soils. Snowberry grows well in sun or shade.

More info for the term: shrub

Common snowberry is a native, deciduous, shrub that is densely branched. Plants vary in height from 3 to 4.5 feet (1-1.5 m) [50,70,104]. In riparian habitats, common snowberry can reach a height of 6 feet (2 m) [70]. It has a rhizomatous growth habit with rhizomes 2 to 5 inches (5-12.5 cm) deep in mineral soil and commonly forms dense thickets. Flowers are borne in small clusters that produce white drupes. Each drupe contains 2 nutlets with 1 seed per nutlet [50,70,104].

One source [11] reports common snowberry to have a vesicular-arbuscular mycorrhizal relationship in British Columbia. In western Washington, common snowberry has been found to contain allelopathic chemicals [33].

More info for the terms: climax, hardwood, shrub

Across its distribution, common snowberry is classified as dominant or subdominant in a variety of habitat and community types and vegetation associations. Most of these listings are at the warm/dry end of the habitat scale and include classifications as both climax and seral vegetation.

Examples of climax forest habitat types where common snowberry is a subdominant include ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), and subalpine fir (Abies lasiocarpa) [3]. Common snowberry is considered a mid- to late-seral subdominant with ponderosa pine on floodplains in Oregon [68]. Also in Oregon, common snowberry is considered subdominant to Douglas hawthorn (Crataegus douglasii) in a climax tall shrub community type [10] and dominant in a community type with Wood's rose (Rosa woodsii) [67].

Species commonly associated with common snowberry include oceanspray (Holodiscus discolor) in California's hardwood rangelands [4], ninebark (Physocarpus malvaceus) in Oregon [63], bearberry (Arctostaphylos uva-ursi) in south Dakota and eastern Wyoming [3], and Idaho fescue (Festuca idahoensis) in eastern Washington [14].

References describing common snowberry as a community or habitat dominant or subdominant include:

Forest types of the North Cascades National Park Service Complex [2]

Steppe vegetation of Washington Daubenmire 1970 [28]

Ecology of curlleaf mountain-mahogany (Cercocarpus ledifolius Nutt.) in eastern Oregon and adjacent areas [32]

Riparian dominance types of Montana [52]

Forest vegetation of the Black Hills National Forest of South Dakota and Wyoming: a habitat type classification [59]

Riparian reference areas in Idaho: a catalog of plant associations and conservation sites [62]

Ecology and plant communities of the riparian areas associated with Catherine Creek in northeastern Oregon [67]

Vegetation of the Bald Hills oak woodlands, Redwood National Park, California [106]

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This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

102 Idaho fescue

109 Ponderosa pine shrubland

110 Ponderosa pine-grassland

201 Blue oak woodland

202 Coast live oak woodland

203 Riparian woodland

411 Aspen woodland

412 Juniper-pinyon woodland

416 True mountain-mahogany

421 Chokecherry-serviceberry-rose

422 Riparian

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

More info for the term: shrub

K001 Spruce-cedar-hemlock forest

K002 Cedar-hemlock-Douglas-fir forest

K003 Silver fir-Douglas-fir forest

K004 Fir-hemlock forest

K005 Mixed conifer forest

K008 Lodgepole pine-subalpine forest

K010 Ponderosa shrub forest

K011 Western ponderosa forest

K012 Douglas-fir forest

K013 Cedar-hemlock-pine forest

K014 Grand fir-Douglas-fir forest

K015 Western spruce-fir forest

K016 Eastern ponderosa forest

K017 Black Hills pine forest

K018 Pine-Douglas-fir forest

K020 Spruce-fir-Douglas-fir forest

K022 Great Basin pine forest

K023 Juniper-pinyon woodland

K024 Juniper steppe woodland

K025 Alder-ash forest

K026 Oregon oakwoods

K028 Mosaic of K002 & K026

K029 California mixed evergreen forest

K030 California oakwoods

K033 Chaparral

K034 Montane chaparral

K037 Mountain-mahogany-oak scrub

K038 Great Basin sagebrush

K050 Fescue-wheatgrass

K051 Wheatgrass-bluegrass

K055 Sagebrush steppe

K056 Wheatgrass-needlegrass shrubsteppe

K064 Grama-needlegrass-wheatgrass

K066 Wheatgrass-needlegrass

K067 Wheatgrass-bluestem-needlegrass

K069 Bluestem-grama prairie

K074 Bluestem prairie

K081 Oak savanna

K093 Great Lakes spruce-fir forest

K095 Great Lakes pine forest

K096 Northeastern spruce-fir forest

K100 Oak-hickory

K101 Elm-ash forest

K104 Appalachian oak forest

K107 Northern hardwoods-fir forest

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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):

FRES10 White-red-jack pine

FRES11 Spruce-fir

FRES15 Oak-hickory

FRES17 Elm-ash-cottonwood

FRES19 Aspen-birch

FRES20 Douglas-fir

FRES21 Ponderosa pine

FRES22 Western white pine

FRES23 Fir-spruce

FRES24 Hemlock-Sitka spruce

FRES25 Larch

FRES26 Lodgepole pine

FRES28 Western hardwoods

FRES29 Sagebrush

FRES34 Chaparral-mountain shrub

FRES35 Pinyon-juniper

FRES36 Mountain grasslands

FRES38 Plains grasslands

FRES39 Prairie

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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):

1 Jack pine

16 Aspen

18 Paper birch

42 Bur oak

53 White oak

107 White spruce

205 Mountain hemlock

210 Interior Douglas-fir

211 White fir

212 Western larch

213 Grand fir

215 Western white pine

216 Blue spruce

217 Aspen

218 Lodgepole pine

220 Rocky Mountain juniper

222 Black cottonwood-willow

224 Western hemlock

229 Pacific Douglas-fir

230 Douglas-fir-western hemlock

233 Oregon white oak

235 Cotton-willow

237 Interior ponderosa pine

239 Pinyon-juniper

243 Sierra Nevada mixed conifer

244 Pacific ponderosa pine-Douglas-fir

245 Pacific ponderosa pine

246 California black oak

250 Blue oak-foothills pine

251 White spruce-aspen

255 California coast live oak

Common snowberry occurs on a wide variety of soil types [50]. It is tolerant of mildly acidic to moderately alkaline conditions and somewhat tolerant of salts. It can also survive under low nutrient conditions [115]. It does well on soils derived from limestone and not well on soils derived from granitic sources [49]. It is often found on disturbed, coarse-textured and rocky soils in Alberta [115]. It does best on well-drained soils [51,52,118].

These well-drained sites can range from warm dry slopes and open forests (where it is used as an indicator species) [51] to warm moist slopes [118] to riparian benches and terraces [52]. It will grow in partial shade, but prefers more open sites [115]

Elevation ranges for some western states include [3]:

 4,200 to 6,700 feet (1,572-2,061 m) in South Dakota
 5,500 to 7,900 feet (1,676-2,408 m) in Colorado
 4,200 to 8,300 feet (1,572-2,553 m) in Wyoming
 2,600 to 6,300 feet (800-1,938 m) in Montana
 7,700 to 9,200 feet (2,389-2,831 m) in Colorado and New Mexico
 2,600 to 5,400 feet (800-1353 m) in Idaho and Washington

Comments: Common snowberry occurs on dry to moist, well-drained sites in sun or partial shade, including thickets, woods, and open slopes from lowlands to mid-elevation in mountains.

Propagation by Seed: Symphoricarpos albus seeds are best sown in the fall after maturity. Dormancy of this species is caused by hard seed coat and immature embryo, which can be broken by stratification in sand and peat for 90 days at 77º, plus 180 days at 41ºF. When the seedlings are large enough to handle, place them into individual pots and grow them in the greenhouse for their first winter. Plant seedlings into their permanent positions in late spring or early summer.

Symphoricarpos albus (Snowberry)
(according to Graenicher, all insects suck nectar; it is also possible that some bees collect pollen and some flies feed on pollen; all observations are from Graenicher)

Bees (long-tongued)
Apidae (Apinae): Apis mellifera; Apidae (Bombini): Bombus fervida, Bombus pensylvanica, Bombus ternarius, Bombus vagans; Anthophoridae (Anthophorini): Anthophora terminalis; Anthophoridae (Xylocopini): Xylocopa virginica; Megachilidae (Megachilini): Megachile latimanus, Megachile melanophaea; Megachilidae (Osmiini): Hoplitis producta, Osmia albiventris, Osmia distincta, Osmia simillima

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon melliventris, Agapostemon sericea, Agapostemon splendens, Agapostemon virescens, Augochlorella persimilis, Augochloropsis metallica metallica, Lasioglossum imitatus; Colletidae (Colletinae): Colletes aestivalis; Colletidae (Hylaeinae): Hylaeus modestus modestus; Andrenidae (Andreninae): Andrena sp., Andrena miserabilis bipunctata, Andrena pruni, Andrena vicina, Andrena zabriskiei (Ashmead, MS)

Wasps
Sphecidae (Sphecinae): Ammophila kennedyi; Vespidae (Eumeninae): Ancistrocerus adiabatus, Eumenes fraterna, Euodynerus foraminatus, Symmorphus cristatus; Vespidae (Vespinae): Dolichovespula arenaria, Vespula vidua

Flies
Syrphidae: Eristalis anthophorina, Eristalis dimidiatus, Helophilus fasciatus, Helophilus stipatus, Tropidia quadrata; Conopidae: Zodion fulvifrons; Tachinidae: Archytas analis, Belvosia bifasciata, Tachinomyia panaetius; Calliphoridae: Phormia regina; Muscidae: Neomyia cornicina

Butterflies
Nymphalidae: Danaus plexippus, Megisto cymela, Phyciodes tharos; Lycaenidae: Celastrina argiolus

Skippers
Hesperiidae: Thorybes pylades

Moths
Noctuidae: Alypia octomaculata, Anagrapha falcifera, Pseudaletia unipunctata

Beetles
Scarabaeidae: Trichiotinus piger

In Great Britain and/or Ireland:
Foodplant / saprobe
loosely gregarious, immersed, papillate, raising and piercing the epidermis, amber brown with darker pore pycnidium of Ascochyta coelomycetous anamorph of Ascochyta symphoricarpi is saprobic on dead stem of Symphoricarpos albus
Remarks: season: 6

Foodplant / spot causer
pycnidium of Ascochyta coelomycetous anamorph of Ascochyta vulgaris var. symphoricarpi causes spots on live leaf of Symphoricarpos albus
Remarks: season: 6-8

Plant / resting place / on
puparium of Aulagromyza cornigera may be found on leaf of Symphoricarpos albus

Plant / resting place / on
puparium of Aulagromyza hendeliana may be found on leaf of Symphoricarpos albus

Plant / resting place / within
puparium of Chromatomyia lonicerae may be found in leaf-mine of Symphoricarpos albus

Plant / resting place / within
loosely attached puparium of Chromatomyia periclymeni may be found in leaf-mine of Symphoricarpos albus

Foodplant / saprobe
usually tufted colony of Corynespora dematiaceous anamorph of Corynespora pruni is saprobic on Symphoricarpos albus

Foodplant / saprobe
scattered, covered, slightly raising the epidermis, soon erumpent stroma of Cytospora coelomycetous anamorph of Cytospora symphoricarpi is saprobic on dead branch of Symphoricarpos albus
Remarks: season: 9

Foodplant / saprobe
immersed, often loosely grouped perithecium of Diaporthe eres is saprobic on wood of Symphoricarpos albus

Foodplant / feeds on
gregarious, subepidermal pycnidium of Phomopsis coelomycetous anamorph of Diaporthe ryckholtii feeds on branch of Symphoricarpos albus
Remarks: season: 6-8

Foodplant / parasite
Erysiphe symphoricarpi parasitises Symphoricarpos albus

Foodplant / saprobe
immersed, but raising and splitting the epidermis pycnidium of Hendersonia coelomycetous anamorph of Hendersonia fiedleri var. symphoricarpi is saprobic on dead twig of Symphoricarpos albus

Foodplant / saprobe
immersed or erumpent perithecium of Melomastia mastoidea is saprobic on dead branch of Symphoricarpos albus

Foodplant / open feeder
nocturnal larva of Tenthredo vespa grazes on leaf of Symphoricarpos albus

Foodplant / open feeder
larva of Zaraea aenea grazes on leaf of Symphoricarpos albus

Foodplant / open feeder
larva of Zaraea fasciata grazes on leaf of Symphoricarpos albus

Foodplant / open feeder
larva of Zaraea lonicerae grazes on leaf of Symphoricarpos albus
Other: major host/prey

More info for the terms: competition, cover, fuel, rhizome, shrubs, tree

Common snowberry is one of the first species to recolonize a postfire site. New growth provides forage and often bears increased fruit crops. Cover is provided for small wildlife species and lush vegetation can protect soil surfaces from splash erosion, but can also offer severe competition to new tree seedlings. The living rhizome systems can be important in retaining nutrients released by fire [77]. One study [5] found that planting grass seed to control erosion reduced coverage of common snowberry and other native shrubs on several burned sites in Oregon.

In Saskatchewan, to burn common snowberry it is recommended waiting 4 days after heavy rains. In addition, if spring burning, a minimum temperature of 55 degrees Fahrenheit (13 oC), wind speed of 2-12 mi hr-1 (3-19 km hr-1), and a maximum relative humidity of 50% is suggested. After burning, a 2-year wait is needed to build up enough fuel to burn again [9]. Common snowberry may be susceptible to frequent burning [100]. If planting common snowberry, prompt, early spring planting is required or it may experience moisture stress in the short term [36].

Common snowberry has a low surface to volume ratio and will have a high flammability if there are many dead stems [18]. It is capable of producing firebrand material. When located near fire control lanes, it should be red-flagged as spot fire potential [83].

More info for the terms: fire use, prescribed fire, restoration

The following Research Project Summaries also provide information on prescribed fire
use and postfire response of plant community species including common snowberry:

• Vegetation response to
  restoration treatments in ponderosa pine-Douglas-fir forests of western Montana
• Understory recovery after low- and high-intensity fires in northern Idaho ponderosa pine forests
• Understory recovery after
  burning and reburning quaking aspen stands in central Alberta

More info for the terms: cover, fire severity, frequency, rhizome, severity

Common snowberry, as a rhizomatous sprouter, is among the first to recolonize a site after fire [77]. Growth in the 1st postfire year varies, but is generally considered to be good. With light to moderate soil disturbance, sprouting will return common snowberry coverage in a year [36] and common snowberry may produce fruit the 1st year [16]. Sprout height can reach one-half to three-fourths of prefire stem height in the 1st year and equal prefire height in 4 years [84]. Another source [36] states common snowberry will grow 1 foot (0.3 m) the 1st year. Cover and volume measurements consistently exceed prefire values the 2nd year [84] and canopy cover of common snowberry increases rapidly to a maximum in 3 to 5 years after a fire and may maintain this increased coverage [23,80]. Fire severity and soil moisture content at time of burning may determine damage to the rhizome and root system of common snowberry and be responsible for variation in recovery response [52].

On ponderosa pine and Douglas-fir communities in the Blue Mountains of northeastern Oregon, common snowberry cover and frequency were higher on sites that had been thinned 6 years previously than on prescribed burned, thinned-and-burned, or control sites. Common snowberry was determined to be an indicator species for thinned sites (P≤0.05). For further information on the effects of thinning and burning treatments on common snowberry and 48 other species, see the Research Project Summary of Youngblood and others' [120] study.

More info for the terms: density, fire intensity, rhizome

Common snowberry is top-killed by fire, but belowground parts are very resistant to fire [71,77,83,103,118]. Variable response to fire has been reported [23,77,84] but in general, light- to moderate-severity fires increase stem density [15,23,36], and common snowberry survives even severe fires [15,26,84]. To eliminate rhizomatous sprouting, fire intensity must be severe enough to kill the roots and rhizome system [1].

More info for the terms: rhizome, shrub

Rhizomatous shrub, rhizome in soil

More info for the terms: resistance, severity

Common snowberry is classified as a "survivor" [71,103] and has high resistance to fire [26,73,84]. It is a rhizomatous species with rhizomes buried 2 to 5 inches (5-12.5 cm) deep in mineral soil [50,70,104]. After fire has killed the top of the plant, new growth sprouts from these rhizomes [77,83,118]. This rhizomatous growth response is highly variable and depends on conditions at specific sites [23,77,84]. Regeneration from buried seed is favored by fires of low severity and short duration that remove little of the soil organic level [23,55].

Common snowberry occurs in a wide variety of community/habitat types and plant associations (see DISTRIBUTION AND OCCURRENCE). There are many FIRE REGIMES included within these plant communities [15,31,41,42]. To learn more about FIRE REGIMES and fire ecology of communities where common snowberry occurs, refer to the FEIS summary for the dominant species. Community or Ecosystem Scientific name of dominant species Fire return interval in years Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [19] Rocky Mountain ponderosa pine* P. ponderosa var. scopulorum 2-10 [19] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 40-140 [79,107] coastal Douglas-fir* P. menziesii var. menziesii 95-242 [82,91] *Fire return interval varies widely; trends in variation are noted in the species summary.

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More info for the terms: climax, shrub, succession

Common snowberry occurs in early, mid-, and late successional stages and as a climax species. It is considered part of the climax community in the ponderosa pine/common snowberry habitat type in Idaho [101] and with Douglas-fir in warm dry habitat types [7]. It is late seral in ponderosa pine/ninebark habitat type in Idaho [101]. In thinleaf alder (Alnus incana)/common snowberry plant associations in Oregon, it is considered mid-seral [68]. It is included in early seral stages of 2 western hemlock (Tsuga heterophylla) habitat types in Idaho [119].

In general, common snowberry is a shrub characterized by survival through rhizomes. If it is on a site prior to disturbance, it will be become established in the initial postdisturbance year and may dominate early succession [71].

More info for the terms: rhizome, shrub

A common snowberry rhizome sprout.

Common snowberry can regenerate by seeds, but rhizomes are the primary method of reproduction [50,104]. Rhizomes are occasionally connected in a mass of woody tissue from which multiple stems can regenerate; however, separate rhizomes are usually produced from which single stems arise [17]. Rhizomes sprout after fire or other disturbance kills the top of the plant [64,77,103] and can vary from site to site depending on conditions [64,77,84]. Plants sprouting from rhizomes are among the first to recolonize a site after a fire [64,103] and will often produce fruit the 1st growing season [16]. The rhizome sprout pictured above came from a 3-year-old common snowberry in a garden at the Fire Sciences Laboratory. The rhizome was 6.5-foot (2.0 m) long, and the sprout was 2 feet (0.6 m) tall (Fryer 2011, personal observation).

Seed banks of common snowberry were analyzed in a postfire study [80], but the literature contains very little about postfire regeneration from seed. One study in an east-central Washington ponderosa pine/common snowberry community found common snowberry sprouted from roots, rhizomes, underground organs, or other perennial plant parts, but did not establish from seeds [87]. The seeds of this shrub are commonly dispersed by birds after they eat the fruit [104].

Common snowberry seeds will sprout in a nursery setting [54,78,96]. However, nutlets of common snowberry are extremely difficult to germinate because they have a hard, tough, impermeable covering and only a partially developed embryo [38].

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More info for the term: phanerophyte

Phanerophyte

More info for the term: shrub

Shrub

S. ALBUS and related species provide important winter and summer browse for game animals and for sheep and cattle in areas where grasses have cured or where grass cover is less abundant. Several range and forest management studies have looked at encouraging common snowberry growth and monitoring effects of browsing (Willard and McKell 1973, Szukiel 1981).

Another group of studies has looked at the invasion of this species into grasslands (McLean 1969, Anderson and Bailey 1979, Agee and Dunwiddie 1984). Most research on the species has involved manipulations of individual plants and/or communities, and little literature exists on plant reproduction or ecology in unmanipulated settings.

Willard and McKell (1973) clipped SYMPHORICARPOS VACCINIOIDES for five years to simulate browsing. Treatments involved clipping at the same time each year, under deferred-rotation, alternate rest, and rest rotation grazing systems, each at three intensities (30%, 60%, and 90%) of herbage removal. Sprout numbers were higher in all of the clipping treatments, increasing with increased percent herbage removal. However, sprout mortality increased propor- tionately. Carbohydrate reserves were lowered by annual clipping in July. Future production of twigs, leaves and seeds was reduced by annual 60-90% herbage removals in early or mid-season. However, 30% herbage removal stimulated future production of leaves and twigs.

George and McKell (1978a, 1978b) studied seasonal patterns in car- bohydrate reserves in S. OREOPHILUS. Nonstructural carbohydrate reserves were lowest in May due mainly to a reduction in nonstruc- tural carbohydrate (NC) reserves in small roots and old stems. Carbohydrate levels in large roots and root crowns remained relatively stable seasonally. NCs for leaf production appear to come from stems rather than roots and followed a declining trend in plants fully defoliated at two-week intervals from June 1 to July 15, and on May 15, May 30, and June 15 the second year (George and McKell 1978a). Plants receiving this treatment died at the end of two years.

McLean (1969) categorized species based on their fire resistance by looking at rooting characteristics. The root system of S. ALBUS is described as fibrous with rhizomes which grow between 5 and 13 cm below the mineral soil surface and which show signs of being able to regenerate from those depths. It was predicted to be a fire-resistant plant because roots penetrate below depths that experience the greatest increases in temperature during fire.

Anderson and Bailey (1980) conducted burns in grass and shrublands annually for 24 years. Burns were conducted in April when soil moisture was high. The percent cover of SYMPHORICARPOS OCCIDEN- TALIS was much lower in burned plots than unburned plots; however, there was no difference in frequency. In Kansas, annual early spring burning reduced stem densities of S. ORBICULATUS, while late-spring burning eliminated the species entirely (Smith and Owensby 1972).

Westcott (1982) describes a species of tephritid fly, RHAGOLETIS ZEPHYRIA, the snowberry maggot, that oviposits on snowberry fruits. However, no estimates of infestation rates or effects on seed production were given. Because snowberry spreads mostly by vegetative growth and sprouting (Willard and McKell 1973), it is unlikely that reduction of seed production by flies would result in significant decline in snowberry populations.

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More info for the terms: phenology, shrub

Common snowberry initiates budding in early May in the northern Rocky Mountains. This budding can be delayed a month in Canada and Alaska or happen a month early in the Southwest depending on elevation and weather conditions. Leaves are full grown about 1 month after emergence. Flowers appear any time from May to August and may be present as late as September. Peak flowering time is June and July. Fruit ripening times are also variable, but typically occur during late August and early September, coinciding closely with leaf fall [50]. The fruits of this shrub commonly remain on the plant over winter [104].

Phenology for common snowberry east of the Continental Divide in Montana and Yellowstone National Park, Wyoming, is [95]: Leaf buds burst Leaves full grown Flowers start Flowers end Fruits ripe Seed fall starts Leaves start to color Leaves start to fall Leaves fallen Average date May 6 June
14 July
4 July
22 Sept. 2 Sept. 14 Aug. 28 Sept. 9 Sept. 30 Earliest Apr. 10 May
17 June
4 June
10 Aug. 7 Aug. 16 July
20 July
23 Aug. 28 Latest June 7 July
10 Aug.
11 Aug.
21 Oct. 9 Oct. 14 Sep. 25 Oct. 15 Oct. 30

Common snowberry spreads mainly by vegetative means through sprouting (Willard and McKell 1973). It reproduces by rhizomes as well as by seed and resprouts after fire or cutting (Tisdale and Hironaka 1981).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 12
Specimens with Barcodes: 14
Species With Barcodes: 1

The Commonwealth of Massachusetts [72] lists common snowberry as an endangered species.

Virginia classifies common snowberry as very rare within the state [112].

Delaware [34] has common snowberry on their watchlist of rare native plants.

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Reasons: Widespread and abundant in much of North America. In some areas, it is a problem pest species invading grassland habitats.

Please consult the Plants Web site and your State Department of Natural Resources for this plant’s current status, such as, state noxious status and wetland indicator values.

Global Short Term Trend: Increase of 10 to >25%

Comments: S. ALBUS is a potential threat to grassland element occurrences adjacent to woodlands and forests with S. ALBUS in the understory, particularly when fire is suppressed or summer moisture is increased.

More info for the terms: cover, severity

Common snowberry is browsed by cattle but is resistant to heavy browsing [23]. However, in a common snowberry-rose (Rosa spp.) community type in Oregon, common snowberry was reportedly browsed to elimination from the site [63]. On grazed sites in Idaho, common snowberry occupies at least 50% less crown space than on ungrazed sites [22]. Grazing capacity guidelines for some western Montana common snowberry community/habitat types are provided by Williams and others [117]. Common snowberry is sensitive to trampling and soil compaction [118].

Common snowberry responds moderately well after logging depending on site characteristics [8,43,46]. Seven years after logging in ponderosa pine in eastern Washington and Oregon, common snowberry had increased its coverage by 30% over its prelogging coverage [44]. It can be expected to increase in cover and form low thickets following logging and may provide shade to conifer seedlings during their early growth [50]. The expected response of common snowberry to clearcutting and low and high severity site preparation by fire or mechanical means is [81]:MechanicalFirelowhighlowhigh++++++++Where + equals increase and ++ equals an even greater increase.

These species are introduced in Switzerland.

Management Requirements: S. ALBUS is a natural component of many communities but increases with fire suppression and increased summer moisture. S. ALBUS is a potential threat to grassland element occurrences adjacent to woodlands and forests with S. ALBUS in the understory where these conditions occur.

Burning and cutting may be successful control methods for arresting the invasion of SYMPHORICARPOS into grasslands. Due to snowberry's tendency to vigorously resprout, treatments are required over several years. Cutting or burning should be done in late spring or early summer when the effects on S. ALBUS would be most severe. Multiple cuttings in a single year may also speed reductions in S. ALBUS. Annual, late-spring burning may also control the species.

Management Programs: WAFO is experimenting with the herbicide Round-Up. Five plots were sprayed in July 1985.

Management Research Programs: The Washington Field Office is experimenting with the use of the herbicide Round-Up in snowberry control.

Management Research Needs: More experimentation with methods of control is needed.

Commonly available through native plant nurseries, except in the south. Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”

Snowberry fruit contains low concentrations of a bitter principle, saponin, which foams in water. It is very poorly absorbed by the body and can be broken down by thoroughly cooking the fruit. Saponin is much more toxic to some creatures, such as fish, if eaten in large quantities.

Ethnobotanic: Some southern groups made brooms out of the branches and the Gitksan hollowed out the twigs to make pipe-stems (MacKinnon, Pojar, & Coupe´ 1992). One or two of the berries were eaten by the Stl’atl’imx to settle the stomach after too much fatty food (Pojar & MacKinnon 1994). An infusion of the fruit was used as eyewash for sore eyes and the berries were rubbed on the skin as treatment for burns, rashes, and sores (Moerman 1998). A decoction of the roots and stems was used in the treatment of the inability to urinate, venereal diseases, tuberculosis and the fevers associated with teething sickness (Ibid.). A tea made from the roots of this species was used to clear up afterbirth (Fielder 1975).

Wildlife: Snowberry is an important browse for many types of livestock and wildlife. It is important for shelter and food for various birds and small mammals.

Stewardship Overview: More information on the cause of the increase in SYMPHORICARPOS ALBUS and documentation of rates of spread is needed. Research on methods of control, especially fire and cutting, are also needed.