Viburnum opulus s.l.
Technical Pageby Steven D. Glenn
Not peer reviewed
Last modified: 01/25/2013
Viburnum opulus opulus Weston, Bot. Univ. 1: 308. 1770.
Viburnum lobatum Lam., Fl. Franc. 3: 363. 1778.
Opulus trilobofolia Gilibert, Fl. Lithuan. 1: 2. 1781.
Viburnum opulus var. europaea Ait., Hort. Kew. 1: 372. 1789.
Viburnum lobatofolia Gilibert, Exerc. Phytol. 1: 4. 1792.
Opulus glandulosa Moench, Meth. Pl. 505. 1794.
Viburnum glandulosum Salisbury, Prodr. Stirp. Chap. Allert. 172. 1797.
Opulus vulgaris Borkhausen in Arch. Fur Bot. (Roemer), 1,2: 20. 1797.
Viburnum opulus var. europeanum Michx., Fl. Bor.-Am. 1: 180. 1803.
Opulus palustris S. F. Gray, Nat. Arr. Brit. Pl. 2: 489. 1821.
TYPE: unknown (Lectotype: Herb. Clifford: 109, Opulus 1' fol. A, BM), designated by Malecot, 2002.
Viburnum opulus var. americana Ait., Hort. Kew. 1: 373. 1789.
Viburnum trilobum Marsh., Arbust. Am. 162. 1785.
Viburnum opulus var. pimina Michx., Fl. Bpr.-Am. 1: 180. 1803.
Viburnum pimina Raf., Med. Repos. New York, hex. 2, 5: 354. 1808.
Viburnum opuloides Muhlb., Cat. Pl. Am. Sept. 32. 1813.
Viburnum oxycoccus Pursh, Fl. Am. Sept. 1: 203. 1814.
Viburnum edule Pursh, Fl. Am. Sept. 1: 203. 1814, p.p.; not Raf. 1808.
Viburnum opulus sensu Torrey & Gray, Fl. N. Am. 1: 18. 1841.
Opulus oxycoccus Bercht. & Presl, Pririov. Rostlin, 2: 97. 1825. ex B. D. Jackson in Index Kew. 2: 356. 1894.
Viburnum americanum sensu Dippel, Handb. Laubh. 1: 173. 1889.
Viburnum opulus ssp. trilobum (Marsh.) R.T.Clausen, Cornell Univ. Agric. Exp. Sta. Mem. 291: 10. 1949.
HABIT Perennial, deciduous, phanerophytic, shrub, monoclinous, 1-4 m tall.
STEMS Main stems ascending or erect, round. Bark smooth, not exfoliating, light brown or gray. Branches ascending. Twigs light brown or gray, terete, 2-4 mm in diam., smooth, glabrous, with sessile, dark orange-red glands or eglandular. 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 Axillary present (terminal buds almost never produced because the terminal vegetative shoots die back to the first pair of lateral buds; unusual among viburnums Donoghue, 1981), scattered along stem; axillary buds 1 per axil. Bud scales 2, red or green, valvate, glabrous. Leaf scars thinly crescent-shaped. Vascular bundle scars 3.
LEAVES Opposite, simple, 2 per node, spaced somewhat evenly along stem, divergent from stem. Stipules present, lateral, persistent or deciduous, adnate with the petiole, leaf-like, occasionally morphing into stalked glands; occasionally more than 2, (histological studies have shown that there occur specialized marginal meristems in the "stipules" comparable to the marginal meristems in the lobes and main axis of the blades, and provascular tissue in the center, suggesting that these "stipules" are in fact reduced leaf lobes which may produce glands at their apices Cross, 1938). Leaves petiolate, petiole furrowed, 1-3 cm long, glabrous, with 1-6 sessile or stalked large glands with disks at the distal end; occasionally with smaller red-orange sessile glands scattered throughout. Leaf blades: abaxial surface light green, adaxial surface green, bilaterally symmetric, 6-12 cm long, 6-10 cm wide, chartaceous, base obtuse or truncate, margin palmately lobed and dentate, apex acute, abaxial surface glabrous or with long and unbranched erect or spreading white hairs, sparsely to moderately densely distributed throughout; not glabrescent, dark orange-red sessile glands present or eglandular. Adaxial surface with short and unbranched appressed or spreading white hairs, sparsely distributed throughout; not glabrescent, dark orange-red or black sessile glands present or eglandular. Leaf lobes symmetrical, 3, apex acute, 1/4 - 1/2 the distance to the midvein, sinuses rounded or acute.
INFLORESCENCES Bisexual, compound, terminal umbelliform cyme; glabrous, dark orange-red glands present or eglandular. Peduncle 1.5-5 cm long, glabrous. Bracts sessile, green, linear triangular, margin ciliate, apex acute, caducous. Bracteoles 0 or 1, at base of pedicel or at apex of pedicel, bracteoles: abaxial surface light yellowish green, often streaked with rose-pink, linear triangular, margin entire, apex acute, glabrous, eglandular.
FLOWERS Serotinous, formed on last season's growth, bisexual, with sepals and petals readily distinguishable from one another, 5-merous, fragrance absent, (longer pedicled marginal flowers sterile and enlarged, often reaching anthesis before inner fertile flowers). Calyx actinomorphic, tubular, of fused sepals, persistent, abaxial and adaxial surfaces yellowish green. Tube 1.5-2 mm long, 0.75 mm wide, occasionally with sessile, dark orange-red glands. Sepal lobes 5, triangular, margin entire, apex acute, abaxial surface glabrous, eglandular. Corolla actinomorphic, of fused petals, deciduous, abaxial and adaxial surfaces white. Petal lobes 5. 1.5-2 mm long (petals on marginal sterile flowers .3-1.5 cm long), 1.5-2 mm wide, margin entire, apex obtuse, glabrous, eglandular. Gynoecium syncarpous. Carpels 1. Locules 3, 2 abortive, 1 fertile. Stigmas 1, 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, red, ovoid, 10-12 mm long, 6-8 mm wide, glabrous, often persisting throughout the winter.
SEEDS Seeds 1, yellowish orange, lenticular, 8-10 mm long, 6-7 mm wide, glabrous, pusticulate.
Found in moist to mesic woods, thickets, and roadsides.
A circumpolar species with var. americanum indigenous to northern North America and var. opulus indigenous to northern Eurasia.
United States -- CT, IA, ID, IL, IN, KY, MA, MD?, ME, MI, MN, MO, MT, ND, NE, NH, NJ, NY, OH, OR?, PA, RI, SD, VT, WA, WI, WV, WY
Canada -- MB, NB, NS, ON, QC
New York Metropolitan Region -- While both varieties can be found in the metropolitan region, the nonnative var. opulus appears to be much more prevalent.
Heritage global rank -- G5
Connecticut -- Not listed
New Jersey -- S3 (var. americanum)
New York -- Not listed
Mellitophily -- Andrena, Augochlorella, Dialyctus, Hoplocampa, Lassioglossum, Pirene
Mycophily -- Aedes, Chrysogaster, Chrysopilus, Coenosia, Condylostylus, Corimelaena, Delia, Didea, Dilophus, Eristalis, Hyalomyodes, Lygus, Orthoneura, Platymya, Pollenia, Syrphus, Syritta, Temnostoma, Toxomerus
Cantharophily -- Ampedus, Anthrenus, Cantharis, Carpophilus, Cyrtophorus, Molorchus, Mordella, Trichiotinus
Psychophiliy -- Cisseps, Polites
Myrmecophily -- Formica, Prenolepsis
Endozoochory -- Avian Frugivores: Sturnus vulgaris (Starling), Pinicola enucleator (Pine Grosbeak), Sialia sialis (Eastern Bluebird), 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), 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)
The ripe fruits are very bitter for some time after ripening and usually remain uneaten all winter; in one study the palatability to captive robins declined rather than improved over the winter. The fruits are generally eaten during the following spring. This suggests that species with persistent fruits may depend on years of severe weather and food scarcity for seed dispersal. Jones, 1987
Viburnum opulus seed is slow to germinate due to both the presence of a water-soluble inhibitor in the seed coat and an afterripening requirement; germination is epigeous. Natural germination does not occur during the first year after dispersal. One study of var. americanum indicated that an afterripening regimen with four cycles of alternating temperature (1 week at 20 degrees C and 1 week at 2 degrees C) appeared to be the most suitable treatment, giving a germination rate of over 90 percent. Constant low-temperature treatments have been shown to be ineffective. This species also exhibits seedling dormancy which can 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