Technical Pageby Steven D. Glenn
Not peer reviewed
Last modified: 01/25/2013
Viburnum plicatum Thunb., Trans. Linn. Soc. Lond. 2: 332. 1794.
Viburnum plicatum var. dilatata Lindley in Paxton, Flow. Gard. 1: 147, t. 29. 1851.
Viburnum tomentosum var. sterile K. Koch, Hort. Dendr. 301. 1853.
Viburnum plicatum var. plenum Miq., Ann. Mus. Bot. Lugd.-Bat. 2: 266. 1866.
Viburnum tomentosum var. plicatum Maxim., Bull. Acad. Sci. St. Petersb. 26: 486. 1880.
Viburnum tomentosum var. rotundifolium Hort. ex Rehder in Bailey, Cycl. Am. Hort. : 1925. 1902.
Viburnum tomentosum f. plenum Rehd. in Sargent, Trees & Shrubs 2: 108. 1908.
*Viburnum plicatum f. rotundifolium (Rehd.) Rehd., J. Arnold Arb. 26: 78. 1945.
*Viburnum plicatum f. tomentosum (Thunb.) Rehd., J. Arnold Arb. 26: 77. 1945.
Viburnum dentatum sensu Thunb., Fl. Jap. 122. 1784, not L. 1753.
Viburnum tomentosum Thunb., Fl. Jap. 123. 1784, not Lam. 1778.
Viburnum plicatum var. tomentosum Miq., Ann. Mus. Bot. Lugd.-Bat. 2: 266. 1866. Actinotinus sinensis Oliver in Hooker, Icon. Pl. 18: 1740. 1887.
Viburnum tomentosum f. typicum Zabel in Beissner et al., Handb. Laubh.-Ben. 441. 1903.
Viburnum plicatum was named from the sterile-flowered "snowball" plant found in a garden. Although the wild plant with normal flowers was named first as V. tomentosum this name is illegitimate, having been used earlier for V. lantana. Most current works restrict the use of the specific name to the cultivated snowball-flowered plant while referring all wild plants and other garden selections to f. tomentosum.
HABIT Perennial, deciduous, phanerophytic, shrub, monoclinous, 1-3 m tall.
STEMS Main stems erect, round. Bark smooth, not exfoliating, gray. Branches horizontal. Twigs gray, terete, 3-5 mm in diam., smooth or lenticellate, with two to five-armed fasciculate-stellate brown or light brown hairs, sparsely to densely distributed apically, eglandular, stellate hairs on newer wood; orange lenticullate on older wood. Pith white, round, continuous, nodal diaphram absent. Sap translucent. For a detailed discussion of stem architecture see Donoghue, 1981. For a detailed analysis of the root anatomy see Gasson, 1979.
BUDS Terminal and axillary present, scattered along stem. Dark orange-red, valvate, with two to five-armed fasciculate-stellate brown or light brown hairs, moderately densely or densely distributed throughout. Bud scale scars not encircling the stem. Leaf scars thinly crescent-shaped. Vascular bundle scars 3.
LEAVES Opposite, simple, 2 per node, spaced somewhat evenly along stem, divergent from stem. Stipules absent. Leaves petiolate, petiole furrowed, 1-2 cm long, with two to five-armed fasciculate-stellate hairs, moderately densely to densely distributed throughout; not glabrescent. Leaf blades: abaxial surface light green, adaxial surface green, elliptic or ovate or widely ovate, bilaterally symmetric, 2.5-13 cm long, 2-8 cm wide, chartaceous, base obtuse, margin serrate, apex acuminate or acute, abaxial surface with two to five-armed fasciculate-stellate light brown hairs, moderately densely to densely distributed throughout. Adaxial surface with long and unbranched or two to five-armed fasciculate-stellate light brown hairs, sparsely distributed throughout.
INFLORESCENCES Bisexual, compound, terminal umbelliforn cyme. Peduncle 2-4 cm long, sparsely to moderately densely covered with brown stellate hairs. Rachis absent. Bracts sessile, linear triangular, apex acute, caducous, with two to five-armed fasciculate-stellate light brown hairs, sparsely distributed throughout. Bracteoles 0 or 1, at base of pedicel or at apex of pedicel, linear triangular, apex acute, glabrous or with stellate hairs, caducous.
FLOWERS Serotinous, formed on last season's growth, bisexual (f. plicatum has all enlarged, sterile flowers; f. tomentosum has enlarged, sterile flowers in an outer ring in the inflorescence), with sepals and petals readily distinguishable from one another, 5-merous, fragrance absent, perianth of two whorls. Calyx actinomorphic, tubular, of fused sepals, persistent, abaxial and adaxial surfaces light green, tube 1.5-2 mm long, 0.5-1 mm wide. Sepal lobes triangular, margins entire, apex acute or obtuse, glabrous. Corolla actinomorphic, of fused petals, abaxial and adaxial surfaces white. Petal lobes 5, 2-3 mm long (sterile flowers have petals lobes .5-2 cm long and sometimes tinged rose-pink, and usually reach anthesis before inner fertile flowers), margin entire, apex obtuse, surfaces glabrous. Gynoecium syncarpous. Carpels 1. Locules 3, 2 abortive, 1 fertile. Stigmas 1, lobed, 3-lobed on a short stylopodium at the top of the ovary. Styles 1, short, conical, glabrous. Ovary inferior. Placentation axile or parietal. Androecium epipetalous, exserted, haplostemous. Stamens 5. Anthers yellow, glabrous. Filaments straight, white, glabrous, adnate to base of petals.
FRUITS Drupe, dark blue, ellipsoid, 7-8 mm long, 4-5 mm wide, glabrous, red at first, turning blue-black.
SEEDS Seeds 1, yellow, lenticular, 5-6 mm long, 3-4 mm wide, glabrous, pusticulate.
Usually found in mesic situations.
Indigenous to China and Japan, rarely found escaping from cultivation in northeastern North America.
United States -- CT, MA, MI, NJ, NY, OH, PA
Canada -- ON?, QC?
New York Metropolitan Region -- Nonnative, often found persisting from cultivation or rarely found escaping from cultivation throughout the metropolitan region.
Heritage global rank -- G5
Mycophily -- Temnostoma spp.
Probably Endozoochory -- Avian Frugivores: Pinicola enucleator (Pine Grosbeak), Acanthis flammea (Redpoll), Cardinalis cardinalis (Cardinal), Vireo olivaceus (Red-eyed Vireo), Bonasa umbellus (Ruffed Grouse), Phasianus colchicus (Ring-necked Pheasant), Meleagris gallopava (Turkey), Turdus migratorius (Robin), Sturnus vulgaris (Starling), Catharus minimus (Gray-cheeked Thrush), Catharus guttata (Hermit Thrush), Catharus ustulata (Olive-backed Thrush), Myiarchus crinitus (Great Crested Flycatcher), Bombycilla cedrorum (Cedar waxwing), Dryocopus pileatus (Pileated Woodpecker),
Mammals: Peromyscus spp.(White-footed Mice), Tamias striatus (Chipmunk), Euarctos americanus (Black Bear), Vulpes fulva (Red Fox), Sciurus carolinensis (Eastern Gray Squirrel), Sciurus niger (Eastern Fox Squirrel), Sylvilagus floridanus (Cottontail Rabbit), Mephitis mephitis (Skunk)
Viburnum seed is slow to germinate and most species have embryo dormancy as well as seedling (epicotyl) dormancy and hard seed coats. Germination is epigeous. Stratification at a constant 20 degrees C or a daily alternating temperature of 20 to 30 degrees C for germination followed by a low temperature pre-treatment for seedling production generally gives the best results. Seedling dormancy might be overcome by removal of the cotyledons or by a treatment of gibberellic acid (GA3). Seed can probably be stored in a sealed container at 41 degrees F with little loss of viability after one to two years.
Dried seeds can be stored at low temperature for several years. Young & Young, 1992