New York Metropolitan Flora

Common Names

Western Snowberry

Field Identification

Spreading shrub to 2(3) m high, with arching branches. Leaves opposite, variable in shape and size, generally elliptic, entire to lobed. Flowers in terminal racemes, small, bell-shaped, and pinkish-white. Berry-like fruits bright white at maturity, in clusters at the ends of branches. In the vegetative state, western snowberry can be confused with coralberry (Symphoricarpos orbiculatus). They can be distinguished by pubescence of the current years' twigs. The twigs of S. albus var. laevigatus are glabrous, while the twigs of S. orbiculatus are minutely villous. Also, the fruits of S. albus var. laevigatus are pure white at maturity, while the fruits of S. orbiculatus are red to pink at maturity (starting out white).

Medicinal uses

Disclaimer: The information provided here is for reference and historical use. We do not recommend nor do we condone the use of this species for medicinal purposes without first consulting a physician.

(Moerman, 1998)

Used by Native Americans as an eyewash and a tonic; also used to treat sores.

Other uses

(Moerman, 1998) (Flint, 1983)

Native Americans used the stems to make brooms. Western snowberry is often used as an ornamental shrub because of its decorative white berries.

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Poisonous properties

Disclaimer: The information provided here is for reference and historical use. If you believe you have been poisoned, please contact the Poison Control Office near you (look for the number in the front of the phone book).

(Burrows, 2001)

The fruit and foliage are suspected to be mildly toxic; ingestion can cause mild digestive tract upset and possibly mild sedation. Death is unlikely.

Nomenclature

Note: Jones in his monograph of Symphoricarpos (1940) treats Symphoricarpos albus var. laevigatus at the level of species, for which the earliest eligible name is S. rivularis Suksdorf. Most recent floras, however, continue to follow the treatments of Fernald, 1905 and Blake, 1914, and consider this taxon to be a western variety of the eastern snowberry, S. albus (L.) Blake. To be consistent with current usage, and lacking adequate material to make a judgement on the issue of rank, we continue to use the name S. albus var. laevigatus for the taxon that occurs in our flora. The eastern snowberry (S. albus (L.) Blake ) does not occur in our range, rather more north-westerly or in higher altitudes. The western snowberry is cultivated in our range and occurs in the wild as a relict of cultivation or as a naturalized escape.


*Symphoricarpos albus var. laevigatus (Fern.) Blake, Rhodora 16: 119. 1914.
Symphoria racemosa sensu Loddiges, Bot. Cab. 3: 230. 1818, not Pursh, 1814.
?Symphoria glomerata Raf., Med. Fl. 2: 266. 1830, not Pursh 1814.
Symphoria elongata Presl. ex De Cand., Prodr. 4: 339. 1830.
Symphoria heterophylla Presl. ex De Cand., Prodr. 4: 339. 1830.
Symphoria leucocarpa Hort. ex De Cand., Prodr. 4: 339. 1830.
Symphoricarpos racemosus sensu Hooker, Fl. Bor.-Am. 1: 285. 1833, not Michx. 1803.
Symphoricarpos leucocarpus Hort. ex Bosse, Vollst. Handb. Blumengart. ed. 2, 3: 458. 1842.
Symphoricarpos racemosus var. macrophylla Lavallee, Arb. Segrez. 142. 1877.
Symphoricarpos racemosus var. laevigatus Fernald, Rhodora 7: 167. 1905.
Symphoricarpos hyalinus Heller ex Schneid., Ill. Handb. Laubh. 2: 672. 1911.
Symphoricarpos racemosus var. macrocarpa Anon., Garden, 77: 527, fig. 1913.
Symphoricarpos albus sensu Piper & Beattie, Fl. NW. Coast, 313. 1915, not Blake 1914.
Symphoricarpos rivularis Suksdorf, Werdenda 1: 41. 1927.
TYPE:Lectotype: selected by (Reveal, Mouton & Schuyler, 1999), Proc. Acad. Nat. Sci. Philadelphia. 149: 1-64. 1999.

Diervilla lonicera var. hypomalaca Fern. Rhodora 42:144. 1940.
TYPE: unknown

Description

HABIT Perennial, deciduous shrub, monoclinous, 1-2(3) m tall.

STEMS Main stems ascending to erect, brown to gray, round. Bark smooth, not or slightly peeling, brown to gray. Branches arching. Twigs tan to brown, terete, 1 mm in diam., smooth, glabrous. Pith absent. For a study of root anatomy see Gasson, 1979.

BUDS Axillary only, solitary, scattered along the stem, ovoid, 1.5-2 mm long, pointed, tips elongate. Bud scales 6, tan, imbricate, ovate, chartaceous, abruptly acuminate, glabrous. Bud scale scars encircling the twig. Leaf scars U-shaped, raised, 0.5-1 mm high, 0.5-1 mm wide, glabrous. Vascular bundle scars 1, elliptical, 0.25 mm tall.

LEAVESOpposite, simple, spaced somewhat evenly along and divergent from stem. Stipules absent, interpetiolar line present. Leaves petiolate, petiole furrowed, 0.2-0.7 cm long, sometimes ciliate. Leaf blades: abaxial surface light green to green, scarcely paler than above, adaxial surface green to dark green, elliptic to obovate, bilaterally symmetric, 2-5 cm long, 1.2-4.2 cm wide, base acute, margin entire to sometimes lobed, crenate, or sinuate on leaves of early shoots, ciliate, apex acute or obtuse, mucronate. Abaxial surface glabrous or with a few scattered hairs throughout. Adaxial surface glabrous. Lateral veins 3-7 pairs. Leaf lobes: symmetrical when present, 3-5, apex mucronulate or obtuse, 1/4 - 1/2 the distance to the midvein, sinuses acute.

INFLORESCENCES Serotinous, formed on the current season's growth, bisexual, simple, a terminal raceme or flowers often paired in the uppermost leaf axils. Peduncle 0.2-1.1 cm long, glabrous. Rachis 0.6-1.6 cm long, glabrous. Bracts sessile, green, ovate, curved, 1-2.5 mm long, 1 mm wide, base truncate, margin entire, apex acuminate, glabrous. Bracteoles 2, at apex of pedicel, green, depressed ovate, curved, 0.5 mm long, 1 mm wide, margin entire, apex acute, mucronate, glabrous.

FLOWERS5-merous, with sepals and petals readily distinguishable from one another, 8-10 mm long, 5-6 mm wide, 6-17 or more flowers per inflorescence, perianth of two whorls. Calyx stereomorphic, acetabuliform, of fused sepals, persistent, abaxial and adaxial surfaces green, 3-4 mm long, 2-2.5 mm wide, calyx tube 2-2.5 mm long, 1.5-2 mm wide, calyx limb 0.5-1 mm long, 1 mm wide. Sepal lobes 5, deltate or shallowly triangular, 0.5-1 mm long, 1 mm wide, margin entire, apex acute, abaxial surface glabrous. Corolla of fused petals, zygomorphic, campanulate and strongly ventricose on lower side, glandular-nectariferous inside ventricose portion, whitish-villose inside throat, deciduous, abaxial and adaxial surfaces rosy pink to white, 5-7 mm long, 4-6 mm wide, corolla tube 2-3 mm long, 4 mm wide, corolla limb 1.5-2.5 mm long, 1-2 mm wide. Petal lobes 5, ovate to widely ovate, curved, margin entire, apex obtuse, both surfaces glabrous. Gynoecium syncarpous. Carpels 4? Locules 4, 2 sterile, containing abortive ovules. Stigmas 1, capitate or slightly 2-lobed, 0.5 mm in diameter. Styles 1, not persistent, 2 mm long, glabrous, bulbous at the base. Ovary inferior, 2-2.5 mm long, 1.5-2 mm wide, spindle-shaped, glabrous. Placentation axile. Androecium alternate, epipetalous, included, haplostemous, introrse. Stamens 5, 2 mm long. Anthers oblong, dehiscing along the long axis, opening entire length of anther, bithecal/tetrasporangiate, yellow, glabrous, 1.5-2 mm long, dorsifixed. Filaments straight, yellow, glabrous, free portion 1 mm long. For a study of pollen micro-anatomy see Donoghue, 1985. For a detailed investigation of floral micro anatomy and morphology see Wilkinson, 1948. For a study of floral ontogeny and the micro-anatomy of the gynoecium see Roels & Smets, 1996.

FRUITS Dipyrenous berry-like drupes, white, subglobose, 7-12 mm long, 7-12 mm wide, glabrous, in terminal glomerules.

SEEDS (Nutlets) 2, white, oval, plano-convex (flattened on one side), obtuse at each end, 4-6 mm long, 2.5-3 mm wide, glabrous, testa smooth.

Habitat

Somewhat dry to mesic roadsides, thickets, and woods.

Distribution

United States -- AK, CA, CO, CT, ID, IL, IN, MA, MD, ME, MI, MO, MT, NC, NH, NJ, NY, OH, OR, PA, RI, TN, VA, VT, WI, WY

Canada -- ON, QC, NB, NF, NS, PE

NYMF: Cultivated in our area, occasionally escaping and becoming naturalized. Found in scattered, isolated localities throughout the metropolitan area.

Rarity Status

Heritage global rank -- G5

Connecticut -- Not listed

New Jersey -- Not listed

New York -- Not listed

Species Biology

Flowering

Jun [week 2]-Aug [week 1] (-Sep [week 1])

Pollination

(Ferguson, 1966) Pollination appears to be chiefly by Hymenoptera.

Based on S. alba: (Graenicher, 1900)
Mellitophily -- Ammophila, Andrena, Agapostemon, Alcidamea, Apis, Augochlora, Bombus, Clisodon, Colletes, Eumenes, Halictus, Megachile, Odynerus, Osmia, Prosopis, Vespa

Mycophily -- Archytas, Belvosia, Eristalis, Helophilus, Lucilia, Peleteria, Phormia, Sturmia, Tachina, Tropidia, Zodion

Psychophily -- Anosia, Lycaena, Neonympha, Phycoides, Thorybes

Phalaenophily -- Alypia, Leucania, Plusia

Cantharophily -- Trichius

Fruiting

Jul [week 4]-Aug [week 4]

Dispersal

Germination

(Snyder, 1991) (Flemion, 1934) (Flemion, 1942) Double dormant, scarification required, after-ripening required. Delayed germination in snowberry is due to a hard, impermeable seed coat and dormancy of the embryo. The effect of the seed coat can be overcome by keeping the seeds in a moist medium (peat moss) at 25ºC for 3-4 months. This can be reduced to 2-4 weeks if the seeds are treated with concentrated sulfuric acid for 30-40 minutes prior to being mixed in the moist peat moss. The dormancy of the embryo can be subsequently broken by an after ripening period of 5-6 months at 5ºC.
(Hidayati, et al., 2001)
(Based on S. orbiculatus) In nature, most seeds germinate in the second spring following maturity. Seeds have nondeep complex morphophysiological dormancy. Cold stratification is effective only following warm stratification.