Possum-haw. Summary. Protection Endangered in New York State, not listed federally.

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1 Possum-haw Viburnum nudum leaves Scientific Name Family Name Viburnum nudum var. nudum Caprifoliaceae Honeysuckle Family Did you know? This beautiful shrub was introduced into cultivation as early as 1752 and has been grown in temperatures as low as -25 degrees F (Dirr 1975) even though in New York it is mostly native to southeastern New York, Staten Island, and Long Island where it rarely, if ever, gets that cold. Photo credits: Stephen M. Young Summary Protection Endangered in New York State, not listed federally. This level of state protection means: listed species are those with: 1) 5 or fewer extant sites, or 2) fewer than 1,000 individuals, or 3) restricted to fewer than 4 U.S.G.S. 7 ½ minute topographical maps, or 4) species listed as endangered by U.S. Department of Interior. Rarity G5T5, S1 A global rarity rank of G5T5 means: Secure globally - Both the species as a whole and the subspecies/variety are common in the world; widespread and abundant (but may be rare in some parts of its range). A state rarity rank of S1 means: This plant is endangered/critically imperiled in New York because of extreme rarity (typically 5 or fewer populations or very few remaining individuals) or is extremely vulnerable to extirpation from New York due to biological factors. Conservation Status in New York There are four existing populations but only one of them has more than 100 plants. The other ones have less than 10 each. There are two historical occurrences which need more checking but are probably gone. NYNHP Conservation Guide - Possum-haw (Viburnum nudum var. nudum)

2 Short-term Trends The short-term trend appears somewhat negative. Some of the small populations have not been seen again and may have disappeared. Long-term Trends The long-term trend is apparently negative. This species has always been very rare in New York and populations remain at low levels. Conservation and Management Threats Development of a hotel complex has threatened one population but the remaining populations have remained stable. Conservation Strategies and Management Practices Research Needs Avoid disturbance of the wetland habitat. Research is needed to see if present populations can be augmented where they exist. Habitat On Long Island, this species is associated with white cedar swamps along streams within pine barrens. On Staten Island it is associated with sweetgum swamps (New York Natural Heritage Program 2012). Associated Ecological Communities Coastal Plain Atlantic White Cedar Swamp A swamp that occurs on organic soils along streams and in poorly drained depressions of the coastal plain. Atlantic white cedar makes up over 50% of the canopy cover. In mixed stands in New York, red maple is the codominant tree. Red Maple-sweetgum Swamp A hardwood swamp that occurs on somewhat poorly drained seasonally wet flats, usually on somewhat acidic soils. Red maple-sweetgum swamps often occur as a mosaic with upland forest communities. Sweetgum is often the dominant tree or may be codominant with red maple. Other codominant trees include pin oak and blackgum. Associated Species Red Maple (Acer rubrum) Oblong-leaf Serviceberry (Amelanchier canadensis) Atlantic White Cedar (Chamaecyparis thyoides) Coast Pepper-bush (Clethra alnifolia) Blue Huckleberry (Gaylussacia frondosa) NYNHP Conservation Guide - Possum-haw (Viburnum nudum var. nudum) 2

3 Sweet Gum (Liquidambar styraciflua) Swamp White Oak (Quercus bicolor) Pin Oak (Quercus palustris) Red Oak (Quercus rubra) Black Oak (Quercus velutina) Swamp Azalea (Rhododendron viscosum) Highbush Blueberry (Vaccinium corymbosum) Southern Arrowwood (Viburnum dentatum) Northern Fox Grape (Vitis labrusca) Identification Comments Possum-haw is a shrub that grows to 4 meters tall. The opposite, petiolate leaves are mostly elliptic or oblong to oblong-lanceolate in shape with smooth margins that can sometimes be a little wavy. The tip and base are acute. They are shiny on the upper surface and very veiny on the lower surface. The winter buds are reddish brown to gray-brown. The ultimate flower cluster peduncles average 3.5 cm long when in flower. The pink fruits mature to a blue color. The stone of the fruit is round-obovate and the pulp is usually bitter-tasting (Gleason and Cronquist 1991). Best Life Stage for Identifying This Species This shrub can be identified vegetatively but is best identified in flower and/or fruit. The Best Time to See This plant flowers in June through July. Fruits persist through October. Vegetative Flowering Fruiting Similar Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec The time of year you would expect to find Possum-haw in New York. Northern wild-raisin, Viburnum nudum var. cassinoides, looks very similar and sometimes overlaps in range but its leaves are dull and not shiny on the top and the veins are not as distinct underneath. The margins have low rounded teeth. The winter buds are yellow-brown or golden. The ultimate flower cluster peduncles average 1.3 cm long when in flower. The stone in the fruit is elliptic or oblong-elliptic and the pulp is sweet (Gleason and Cronquist 1991). Silky Dogwood, Cornus amomum, may also look similar but the leaf venation in dogwoods is arcuate and not the straighter pinnate veins of Viburnum. Taxonomy NYNHP Conservation Guide - Possum-haw (Viburnum nudum var. nudum) 3

4 Kingdom Phylum Plantae Anthophyta Class Dicots (Dicotyledoneae) Order Dipsacales Family Caprifoliaceae (Honeysuckle Family) Additional Common Names Smooth Withe-rod Additional Resources Links Duke University fact sheet Virginia Tech Fact Sheet USDA Plants Database VIBURNUM+NUDUM+VAR+NUDUM NatureServe Explorer AR+NUDUM Google Images Best Identification Reference Gleason, Henry A. and A. Cronquist Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp. References Dirr, M.A Manual of Woody Landscape Plants. Stipes Publishing Company, Champaign, Illinois pp. Fernald, M.L Gray's manual of botany. 8th edition. D. Van Nostrand, New York pp. Holmgren, Noel The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. Keys, Jr.,J.; Carpenter, C.; Hooks, S.; Koenig, F.; McNab, W.H.; Russell, W.;Smith, M.L Ecological units of the eastern United States - first approximation (cd-rom), Atlanta, GA: U.S. Department of Agriculture, Forest Service. GIS coverage in ARCINFO format, selected imagery, and map unit tables. Little, E.L., Jr Checklist of United States trees (native and naturalized). Agriculture Handbook No U.S. Forest Service, Washington, D.C. 375 pp. NYNHP Conservation Guide - Possum-haw (Viburnum nudum var. nudum) 4

5 NatureServe NatureServe Central Databases. Arlington, Virginia. USA New York Natural Heritage Program Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY. Weldy, T. and D. Werier New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research University of South Florida New York Flora Association Albany, New York New York Natural Heritage Program 625 Broadway, 5th Floor, Albany, NY Phone: (518) This project is made possible with funding from: - New York State Department of Environmental Conservation Hudson River Estuary Program - Division of Lands & Forests, Department of Environmental Conservation - New York State Office of Parks, Recreation and Historic Preservation Information for this guide was last updated on Aug 15, 2017 This guide was authored by Stephen M. Young NYNHP Conservation Guide - Possum-haw (Viburnum nudum var. nudum) 5