Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicotyledons

Order: Dipsacales

Family: Caprifoliaceae -- honeysuckle

Variety: S. albus var. laevigatus is the common western phase, but var. albus is also found.

Common Name: common snowberry

Species Code: SYAL

Origin: A widespread shrub native to riparian areas, mesic grasslands and open forests over much of North America except the southeastern US.

Rare: no

Form: shrub, deciduous, erect, branched, rhizomatous, thicket forming, 0.5-2 m tall; twigs thin, generally glabrous, older bark shredding.

Mature height: 20-80 inches

Duration: perennial

Longevity: long-lived

Habitat Type: prairie, shrub thicket, forest

Wetland Indicator Status: FACU

Leaves: opposite, short petiolate, elliptic to elliptic-ovate, 1.5-5 cm long and 1-3.5 cm wide (sometimes larger and irregularly lobed on new shoots), margins entire or irregularly toothed, sparsely hirsute-puberulent or sometimes glabrous above.

Flowers: borne in a short, few-flowered (usually 8-16) raceme on the terminal end of twigs and in the upper leaf axils; corolla pink to white, campanulate, somewhat ventricose, hairy inside, the 5 lobes from as long as to half as long as the tube.

Flower color: pink, white

Bloom: June, July, with a few plants still flowering in August

Bloom starts on: mid June

Bloom ends on: early August

Fruit: drupe, berry-like, white, subglobose or ellipsoid, 8-12 mm wide, often persistent into winter, containing two oblong nutlets 4-6 mm long and 2.5-3.5 mm wide.

Characteristics:
S. racemosus laevigatus in Piper & Beattie 1914. S. rivularis in St. John 1963 and in Davis 1953.
76,000 seeds per lb (Kingery et al 2003).
76,029 seeds/lb (USDA NRCS PLANTS Database 2009).
x=9, 2n=72 (University of British Columbia 2003).
n= about 27 (Hitchcock et al 1969).
Polyploidy is present.
S. albus var. laevigatus has been widely naturalized in Great Britain where it is pollinated by many species of bees, wasps, and flies (Gilbert 1995).
Flowers are perfect.
Fruit is a berry-like drupe.
Human consumption of large quantities of fruit may cause poisoning. Native peoples used the plants medicinally.
Seeds are dispersed by animals which eat the fruit (Walker undated).
Rodents eat the seeds but not the fleshy drupe (Skinner, personal observation).
Fruits are eaten by black bear, Ursus americanus (Auger et al 2002).
Highly valuable browse for Rocky Mountain elk in summer, fall, and winter (Kufeld 1973).
Livestock and large wildlife may browse the plants, however Stubbendieck et al (1997) state it is of little value to livestock.
Plants provide cover for birds and small mammals. Deer sometimes browse the foliage. Fruits remain on the plants into winter, providing food for birds and mammals.
Snowberry is a host for the larva of the Chalcedon checkerspot (Euphydryas chalcedona) butterfly (Pocewicz 2005).
In the absence of insect pollinators, herkogamy probably prevents self pollination (Gilbert 1995).

Comments: S. albus is one of the defining species of the Palouse Prairie. The Festuca idahoensis-Symphoricarpos albus habitat type (h.t.) is the most important h.t. on the deep soils of the Palouse. S. albus is often present as short, usually single stemmed and sterile plants mixed in with the herbaceous layer. S. albus also occurs in thickets of taller and fertile plants contained within the matrix of the Festuca idahoensis-Symphoricarpos albus h.t. and the thickets are considered a phase of that h.t (Daubenmire 1970).

Sun requirement: full sun to partial shade

Soil moisture: mesic

Precipitation: 12-45 inches (USDA NRCS PLANTS Database 2009).

Fire: Symphoricarpos albus is resistant to fire because the roots and rhizomes are deep enough below mineral soil to afford them protection and they are able to regenerate from that depth (McLean 1969).
Rhizomes are deep in mineral soil and allow the plant to survive most fires. Seed regeneration is favored by low intesity fires. Increases rapidly the year following a fire (McWilliams 2000).
Rhizomes and crown are somewhat resistant to fire. Post-fire cover and frequency often remains the same (Crane & Fischer 1986).

Hazards: in large quantities drupes are poisonous

Sowing time: summer

Transplant time: spring

Stratification: warm moist followed by cold moist

Seed yield: high

Seed harvest: difficult

Seed first harvest: 2-3 years from cuttings

Seed cleaning: difficult

Planting duration: long

Seed insect problem: none noted

Seed shatter: low

Seed size: medium

Seed harvest date: October

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Keywords: native perennial upland shrub

Alternate Species: racemosus, rivularis

Alternate Variety: laevigatus, albus

Notes: Can be aggressive and probably is not suitable for a formal landscape, but is a good species for natural areas and wildlife plantings (Idaho Native Plant Society 1999).

References:
Auger, Janene, Susan E. Meyer, and Hal L. Black. 2002. Are American Black Bears (Ursus americanus) Legitimate Seed Dispensers for Fleshy-fruited Shrubs? American Midland Naturalist 147(2):352-367.

Daubenmire, R.F. 1970. Steppe Vegetation of Washington. Washington State Univ. Coop. Ext. Service EB 1446. Pullman, WA.

Davis, Ray J. 1952. Flora of Idaho. Wm. C. Brown, Dubuque, Iowa. 827 pp.

Gilbert, Oliver L. 1995. Biological Flora of the British Isles: Symphoricarpos albus (L.) S.F. Blake (S. rivularis Suksd., S. racemosus Michaux). Journal of Ecology 83:159-166.

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Idaho Native Plant Society. 1999. Native Plants of Northern Idaho for Landscaping and Restoration. INPS White Pine Chapter. Moscow, ID. Online at http://www.idahonativeplants.org/guides/NorthIdahoGuide.aspx

Kingery, James, Angela Cotter, and Kendra Moseley. 2003. Idaho Roadside Revegetation Handbook. Prepared for: Idaho Transportation Department. Department of Rangeland Ecology and Management, University of Idaho. Online at http://h237-41.state.id.us/highways/ops/maintenance/Manuals/fullVegetationManual.pdf

Kufeld, Roland. 1973. Foods Eaten by the Rocky Mountain Elk. Journal of Range Management 26:106-113.

McLean, Alastair. 1969. Fire Resistance of Forest Species as Influenced by Root Systems. Journal of Range Management 22:120-122.

McWilliams, Jack. 2000. Symphoricarpos albus. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2009, November 28].

Piper, C.V., and R.K. Beattie. 1914. The Flora of Southeastern Washington and Adjacent Idaho. Press of the New Era Printing Company, Lancaster, PA. 296 pp.

Pocewicz, Amy. 2005. Host Plants of Palouse Butterfly Species. 2 page handout to accompany the April 2005 presentation to the Palouse Prairie Foundation.

Skinner, David M. Personal observation. Database editor and formerly with the USDA NRCS Pullman Plant Materials Center (retired).

St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA.

Stubbendieck, James, Stephan L. Hatch, and Charles H. Butterfield. 1997. North American Range Plants. 5th edition. University of Nebraska Press, Lincoln, NE. 501 pp.

University of British Columbia. 2003. British Columbia Flora. University of British Columbia Botanical Garden and Centre for Plant Research. Accessed 9/1/09 online at http://www.bcflora.org/

USDA NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 27 November 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Walker, Scott C. undated. Symphoricarpos Duham. snowberry. In: Bonner, Franklin T., and Rebecca G. Nisley (eds.). Woody Plant Seed Manual. USDA Forest Service. Available online at http://www.nsl.fs.fed.us/wpsm/

Links:
Plant Profile from the USDA PLANTS Database
Species account from the Fire Effects Information System
Species information from the University of Washington Herbarium