New York Metropolitan Flora

Genus: Ulmus

Ulmus americana
Ulmus americana   L.  -  American Elm
Photo © by Steven Clemants
Taken at Prospect Park, Brooklyn, NY, 1996.

By Science Staff

Not peer reviewed

Last Modified 03/19/2013

Back to Ulmaceae


Ulmus L., Sp. Pl. 225. 1753. Gen. Pl., ed. 5, 106. 1754. LECTOTYPE: Ulmus campestris L., designated by Britton & Brown (1913).

Microptelea Spach, Ann. Sci. Nat. Bot. ser. 2. 15: 358. 1841. TYPE: Microptelea parvifolia (Jacq.) Spach (=Ulmus parvifolia Jacq.).

Key to the species of Ulmus

1. Leaf blades less than 7 cm...Ulmus pumila
1. Leaf blades greater than 7 cm...2

2. Upper surfaces of leaves rough, sandpapery...4
2. Upper surfaces of leaves smooth...3

3. Samaras pubescent on the sides; inflorescences racemes; older branches with cork-ridges...Ulmus thomasii
3. Samaras glabrous on the sides; inflorescences fascicles; older branches without cork-ridges...Ulmus americana

4. Older twigs with corky wings...Ulmus minor (U. procera)
4. Older twigs lacking corky wings...5

5. Leaves ciliate; buds covered with rusty hairs; fruit pubescent...Ulmus rubra
5. Leaves not ciliate; buds pale-pubescent or glabrous; fruit glabrous...6

6. Young branches pubescent; fruit with the seed in the middle...Ulmus glabra
6. Young branches glabrous; fruit with the seed above the middle (commonly cultivated)...Ulmus ×hollandica

List of Ulmus Species

References to Ulmus

  • Ager, A. A.; Guries, R. P. 1982. Barriers to interspecific hybridization in Ulmus americana. Euphytica 31: 909-20.
  • Angeles, G.; Evert, R. F.; Kozlowski, T. T. 1986. Development of lenticels and adventitious roots in flooded Ulmus americana seedlings. Canad. J. Forest Res. 16: 585-90.
  • Barton, L. V. 1939. Storage of elm seeds. Contr. Boyce Thompson Inst. Pl. Res. 10: 221-33.
  • Bate-Smith, E. C.; Richens, R. H. 1973. Flavonoid chemistry and taxonomy in Ulmus. Biochem. Syst. Ecol. 1(3): 141-6.
  • Beattie, R. K. 1933. How the Dutch elm disease reached America. Proc. Annual Meeting Natl. Shade Tree Conf. 9: 101-5.
  • Bechtel, A. R. 1921. The floral anatomy of the Urticales. Amer. J. Bot. 8: 386-410.
  • Billings, F. H. 1905. Precursory leaf-serrations of Ulmus americana. Bot. Gaz. 40: 224-5.
  • Bob, C. F.; Redmond, B. L.; Karnosky, D. F. 1986. On the nature of intra- and interspecific incompatability in Ulmus. Amer. J. Bot. 73(4): 465-74.
  • Borthwick, H. A. 1957. Light effects on tree growth and seed germination. Ohio J. Science 57: 357-64.
  • Broadhurst, J. 1917. Self-pruning in the American elm. Torreya 17: 21-4.
  • Brown, R. L. 1904. Wood structure of elms, maples and oaks as a means of identifying species. Rep. Michigan Acad. Sci. 4: 109-12.
  • Carter, J. C. 1975. Major tree diseases of the century. J. Arboric. 1(8): 141-7.
  • Cathey, H. M.; Campbell, L. E. 1975. Security lighting and its impact on the landscape. J. Arboric. 1: 181-187.
  • Charlton, W. A. 1993. The rotated-lamina syndrome: 2. The seedling of Ulmus glabra. Canad. J. Bot. 71(2): 222-8.
  • Chernik, V. V. 1980. Peculiarities of structure and development of the pericarp of the representatives of the family Ulmaceae and Celtidaceae. Bot. Zhurn. (Moscow & Lenengrad) 65(4): 521-31. (In Russian)
  • Chernik, V. V. 1975. Arrangement and reduction of perianth and androecium parts in representatives of Ulmaceae Mirbel and Celtidaceae Link. Bot. Zhurn. (Moscow & Lenengrad) 60(11): 1561-73. (In Russian; English summary. See also Inter. Bot. Congress:12 Leningrad- abstract)
  • Choat, B. 2006. Direct measurements of intervessel pit membrane hydraulic resistance in two angiosperm tree species. Amer. J. Bot. 93: 993-1000.
  • Coladoanto, M. 1992. Ulmus americana. ()
  • Coladoanto, M. 1993. Ulmus rubra. ()
  • Collingwood, G. H. 1942. Slippery Elm. Amer. Forests 48: 364-5.
  • Collins, P. E. 1967. Hybridization studies in the genus Ulmus. Ph.D. Dissertation Univ. Minnesota118 p. (Univ. microfilms Dissert. Abstr. 1968, 28 B (12 Pt. 1) 4828-4829)
  • Constantinidou, H. A.; Kozlowski, T. T. 1979. Effects of sulphur dioxide and ozone on Ulmus americana seedlings. I. Visible injury and growth. Canad. J. Bot. 57: 170-5.
  • Constantinidou, H. A.; Kozlowski, T. T. 1979. Effects of sulphur dioxide and ozone on Ulmus americana seedlings. II. Carbohydrates, proteins, and lipids. Canad. J. Bot. 57: 176-84.
  • Dallimore, W. 1920. Elms and elm timber. Quart. J. Forest. 14: 109-18.
  • Dame, L. L.; Brooks, H. 1982. The American elm: Ulmus americana L. Arnoldia (Jamaica Plain) 42: 49-60.
  • Davis, R. W.; Larimore, R. L.; Ebinger, J. E. 1998. The occurrence of slippery elm (Ulmus rubra Muhl.) root sprouts in forest understories in east-central Illinois. Trans. Illinois State Acad. Sci. 91: 13-7.
  • Detwiler, S. B. 1916. The American elm (Ulmus americana). Amer. Forests 22: 259-67.
  • Ehrenberg, C. E. 1953. Studies on elm pollen. Bot. Not. 3: 308-16.
  • Ekdahl, I. 1941. Die Entwicklung von Embryosack und Embryo bei Ulmus glabra Huds. Svensk Bot. Tidskr. 35: 143-56.
  • Elias, T. S. 1970. The genera of Ulmaceae in the southeastern United States. J. Arnold Arbor. 51: 18-40.
  • Elliot, J. C. 1954. Studies in and near Michigan's tension zone: a northward extension for the range of Ulmus thomasi Sarg. Amer. Midl. Naturalist 52: 370-3.
  • George, E. J. 1937. Storage and dewinging of American elm seed. J. Forest. 35: 769-72.
  • Giannasi, D. 1978. Generic relationships in the Ulmaceae, based on flavonoid chemistry. Taxon 27: 331-44.
  • Grudzinskaya, I. A. 1975. On the origin of the American species of Ulmus (hybridogenity and significance of flavonoid score). Bot. Zhurn. (Moscow & Lenengrad) 60(2): 163-9. (In Russian; English summary)
  • Gustafson, F. G. 1950. Is the American elm (Ulmus americana) injured by natural gas? Pl. Physiol. (Lancaster) 25: 433-40.
  • Heybroek, H. M. 1976. Systematics and nomenclature of the genus Ulmus. Groen (Netherlands) 32(8): 237-40. (In Dutch)
  • Higgins, D. J.; Arisumi, T. 1959. Time of floral differentiation in Ulmus americana, U. pumila, and U. carpinifolia. Bot. Gaz. 120(3): 177-80.
  • Hoppes, W. G. 1988. Seedfall pattern of several species of bird-dispersed plants in an Illinois woodland. Ecology 69: 320-329.
  • Jacobs, H. L.; Tehon, L. R. 1939. The study of lightening injury to an American elm. Arborist's News 4(6): 41-4.
  • Johnson, F. L.; Bell, D. T. 1976. Tree growth and mortality in the streamside forest. Castanea 41: 34-41.
  • Johnson, L. P. V. 1946. Fertilization in Ulmus with special reference to hybridization procedure. Canad. J. Forest Res. 24: 1-3.
  • Killingbeck, K. T. 1985. Autumnal resorption and accretion of trace metals in gallery forest tress. Ecology 66: 283-6. (Cu, Fe, Mn, & Zn)
  • Knudsen, G. J. 1978. Rock elm, Ulmus thomasii. Bull. Nat. Resourc. Wisconsin 41(2): 31. (Ref. in Bibliogr. Agric. 42(2):015931. 1978)
  • Kozlowski, T. T.; Pallardy, S. G. 1979. Effects of low temperature on leaf diffusion resistance of Ulmus americana and Fraxinus pennsylvanica seedlings. Canad. J. Bot. 57: 2466-70.
  • Laing, C. C. 1966. Structure, formation, and dormancy of terminal buds of Elm. Bot. Gaz. 127(2-3): 127-32.
  • Lanier, G. N.; Schubert, D. C.; Manion, P. D. 1988. Dutch elm disease and elm yellows in central New York. Plant Dis. 72: 189-94.
  • Lester, D. T. 1971. Self-compatibility and inbreeding depression in American elm. Forest Sci. 17: 321-2.
  • Linder, D. H. 1931. Some diseases of elm trees. Missouri Bot. Gard. Bull. 19: 61-9.
  • Lodhi, M. A. K. 1977. The influence and comparison of individual forest trees on soil properties and possible inhibition of nitrification due to intact vegetation. Amer. J. Bot. 64(3): 260-4.
  • Marshall, P. E.; Kozlowski, T. T. 1974. Photosynthetic activity of cotyledons and foliage leaves of young angiosperm seedlings. Canad. J. Bot. 52(9): 2023-32.
  • McDermott, R. E. 1954. Effects of saturated soil on seedling growth of some bottomland hardwood species. Ecology 35: 36-41.
  • McGregor, R. L. 1985. Multiple seedlings in Celtis (Ulmaceae): with notes on Ulmus americana. Contr. Univ. Kansas Herb. 17: 1-5.
  • Micales, J. A.; Stipes, R. J.; Ratliff, J. L.; Lawrence, S. R. 1981. Botanical aspects of the genus Ulmus. Virginia J. Sci. 32(3): 104. (Abstract)
  • Millet, J. 1998. Plagiotropic architectural development of four tree species of the temperate forest. Canad. J. Bot. 76: 2100-2118.
  • Newhouse, M. E.; Madgwick, H. A. I. 1968. Comparative seedling growth of four hardwood species. Forest Sci. 14: 27-30.
  • Newsome, R. D.; Kozlowski, T. T.; Tang, Z. C. 1982. Responses of Ulmus americana seedlings to flooding of soil. Canad. J. Bot. 60: 1688-95.
  • Oginuma, K.; Raven, P. H.; Tobe, H. 1990. Karyomorphology and relationships of Celtidaceae and Ulmaceae (Urticales). Bot. Mag. (Tokyo) 103: 113-31.
  • Priemer, F. 1893. Die anatomischen Verholtnisse der Laubblotter der Ulmaceen (einschl. Celtideen) und die Beziehungen zu ihrer Systematik. Bot. Jahrb. Syst. 17: 419-75. (In German)
  • Redenbaugh, K.; Karnosky, D. F.; Westfall, R. D. 1981. Protoplast isolation and fusion in three Ulmus species. Canad. J. Bot. 59: 1436-43.
  • Richardson, C. J.; Cares, C. W. 1976. An analysis of elm (Ulmus americana) mortality in a second-growth hardwood forest in southeastern Michigan. Canad. J. Bot. 54(10): 1120-5.
  • Richens, R. H. 1980. On fine distinctions in Ulmus. Taxon 29: 305-12.
  • Roberts, B. R.; Main, H. V. 1965. The effect of chilling and photoperiod on bud break in American elm. J. Forest. 63(3): 180-1.
  • Rowe, J. W.; Seikel, M. K.; Roy, R. N.; Jorgensen, E. 1972. Chemotaxonomy of Ulmus. Phytochemistry 11(8): 2513-7.
  • Santamour, F. S. 1970. A natural hybrid between American and Siberian elms. Forest Sci. 16: 149-53.
  • Santamour, F. S. 1972. Flavonoid distribution in Ulmus. Bull. Torrey Bot. Club 99: 127-31.
  • Santamour, F. S. 1971. A triploid elm (Ulmus pumila x U. rubra) and its aneuploid progeny. Bull. Torrey Bot. Club 98: 310-4.
  • Sargent, C. S. 1895. Ulmus. Silva N. Am. 7: 39-58.
  • Sax, K. 1933. Chromosome numbers in Ulmus and related genera. J. Arnold Arbor. 14: 82-4.
  • Schweitzer, E. M. 1971. Comparative anatomy of Ulmaceae. J. Arnold Arbor. 52: 523-85.
  • Seymour, F. C. 1952. The type of Ulmus americana L. Rhodora 54(641): 138-9.
  • Shattuck, C. H. 1905. A morphological study of Ulmus americana. Bot. Gaz. 40: 209-23.
  • Sherman, S. L. 1987. Flavonoid systematics of Ulmus L. in the United States. M.S. Thesis Univ. Georgia,
  • Sherman, S. L.; Giannasi, D. E. 1988. Foliar flavonoids of Ulmus in eastern North America. Biochem. Syst. Ecol. 16(1): 51-6.
  • Sinclair, W. A. 1972. Phloem necrosis of American elm and slippery elm in New York. Pl. Dis. Reporter 56: 159-61.
  • Sinclair, W. A.; Braun, E. J.; Larsen, A. O. 1976. Update on phloem necrosis of elms. J. Arboric. 2(6): 106-13.
  • Sinclair, W. A.; Griffiths, H. M.; Lee, I. M. 1994. Mycoplasmlike organisims as causes of slow growth and decline of trees and shrubs. J. Arboric. 20(3): 176-89. (Fraxinus & Ulmus)
  • Staub, R. 1967. Some variations in fruit, seed and seedling characteristics in the American elm, U. americana L., in relation to geography of seed source. Diss. Abstr. 28: 511B.
  • Steele, F. L. 1978. Range extension of two New Hampshire trees. Rhodora 80(821): 155.
  • Steinbauer, C. E.; Steinbauer, G. P. 1932. Effects of temperature and desiccation during storage on germination of seeds of the American elm (Ulmus americana L.). Proc. Amer. Soc. Hort. Sci. 28: 441-3.
  • Stipes, R. J.; Campana, R. J. (eds.) (1981): 1981. Compendium of Elm Diseases. St. Paul.
  • Takahashi, M. 1989. Pollen morphology of Celtidaceae and Ulmaceae: a reinvestigation. In: Evolution, systematics and fossil history of the Hamamelidae. 2: Higher Hamamelidae. Clareson Press, Oxford. , 253-65 pages. (Syst. Assoc. Spec. Vol. 40B)
  • Ueda, K.; Kosuge, K.; Tobe, H. 1997. A molecular phylogeny of Celtidaceae and Ulmaceae (Urticales) based on rbcL nucleotide sequences. J. Pl. Res. 110: 171-8.
  • Vozzo, J. A.; Hacskaylo, E. 1964. Anatomy of mycorrhizae of selected eastern forest trees. Bull. Torrey Bot. Club 91: 378-387.
  • Walker, R. I. 1950. Megasporogenesis and development of megagametophyte in Ulmus. Amer. J. Bot. 37: 47-52.
  • Walker, R. I. 1932. Chromosome numbers in Ulmus. Science 75: 107.
  • Walker, R. I. 1938. Macrosporogenesis and embryo development in Ulmus fulva. Bot. Gaz. 99: 592-8.
  • Walters, M. B.; Reich, P. B. 1989. Responses of Ulmus americana seedlings to varying nitrogen and water status. 1. Photosynthesis and growth. Tree Physiology 5: 159-72.
  • Weber, P. V. V.; Sinclair, W. A.; Peterson, J. L.; Davis, S. H. 1974. New in New Jersey: elm phloem necrosis. Pl. Dis. Reporter 58: 387-8.
  • Went, J. C. 1949. Elm nomenclature. Ned. Boschbouw-Tijdschr. 21: 106-8. (In Dutch)
  • Wheeler, E.; LaPasha, C. A.; Miller, R. B. 1988. Woody anatomy of elm (Ulmus) and hackberry (Celtis) species native to the United States. IAWA Bull. 10: 5-26.
  • Whittemore, A. T.; Olsen, R. T. 2011. Ulmus americana (Ulmaceae) is a polyploid complex. Amer. J. Bot. 98: 754-760.
  • Wiegrefe, S. J.; Sytsma, K. J.; Guries, R. P. 1994. Phylogeny of elms (Ulmus, Ulmaceae): molecular evidence for a sectional classification. Syst. Bot. 19: 590-612.
  • Wilkinson, G. 1978. Epitaph for the elm. Hutchinson, London. , 159 pages.
  • Wilson, C. L. 1975. The long battle against Dutch Elm Disease. J. Arboric. 1(6): 107-12.
  • Wright, J. W. 1952. Pollen dispersion of some forest trees.
  • Wright, J. W. 1953. Pollen dispersion studies: some practical applications. J. Forest. 51: 114-8.
  • Wyman, D. 1951. Elms grown in America. Arnoldia (Jamaica Plain) 11: 79-93.
  • Zalapa, J. E. 2009. Patterns of hybridization and introgression between invasive Ulmus pumila (Ulmaceae) and native U. rubra. Amer. J. Bot. 96: 1116-1128.