Genus: Ilex

Ilex opaca
Ilex opaca

By Steven D. Glenn

Not peer reviewed

Last Modified 02/07/2013

Back to Aquifoliaceae


Ilex L., Sp. Pl. 1: 125. 1753. Gen. Pl., ed. 5, 60. 1754. Aquifolium Mill., Gard. Dict. Abr. ed. 4. 1754 (also spelled “Agrifolium”), nom. illeg. (Art. 52.1). Polystigma Meisn., Pl. Vasc. Gen. 1: 252. 1839, nom. illeg. (Art. 52.1). LECTOTYPE: Ilex aquifolium L. designated by Britton & Brown (1913).

Prinos L., Sp. pl. 330. 1753. LECTOTYPE: Prinos verticillatus L. (=Ilex verticillata), designated by Rafinesque (1838).

Macoucoua Aubl., Hist. Pl. Guiane 2(Suppl.): 88. 1775. Ageria Raf., Sylva Tell. 46. 1838, nom. illeg. (Art. 52.1). TYPE: Macoucoua guianensis Aubl. (Ilex guianensis (Aubl.) Kuntze)

Ennepta Raf., Sylva Tellur. 52. 1838. TYPE: Ennepta myricoides Raf., nom. illeg. (Ilex glabra (L.) A. Gray).

Winterlia Moench, Methodus (Moench) 74. 1794. TYPE: Winterlia triflora Moench

Key to the species of Ilex

1. Leaves evergreen...2
1. Leaves deciduous...4

2. Leaves with a spiny margin...Ilex opaca
2. Leaves without a spiny margin...3

3. Leaves with few obtuse teeth near apex or entire; flowers 5-8-merous...Ilex glabra
3. Leaves serrate or crenate, very rarely with only a few teeth near apex; flowers 4-merous...Ilex crenata

4. Sepals entire, even at maturity of the fruit...Ilex laevigata
4. Sepals ciliate, even at maturity of the fruit...5

5. Petals entire or minutely erose; nutlets smooth on back...Ilex verticillata
5. Petals ciliate; nutlets grooved on back...Ilex montana

List of Ilex Species

References to Ilex

  • Ammons, N.; Core, E. L. 1945. The hollies of West Virginia. Castanea 10(2): 57-60.
  • Andrews, S. 1981. Some neglected North American hollies. Int. Dendrol. Soc. Year Book 1980: 134-5.
  • Ashworth, R. P. 1963. Investigations into midvein anatomy and ontogeny of certain species of the genus Ilex. J. Elisha Mitchell Sci. Soc. 79: 126-38.
  • Baas, P. 1973. The wood anatomical range in Ilex (Aquifoliaceae) and its ecological and phylogenetic significance. Blumea 21: 193-258.
  • Barrett, R. E. 1960. Germinating seeds of the American holly. Proc. Holly Soc. Amer. 28: 7-8.
  • Barton, L. V.; Thornton, N. C. 1947. Germination and sex population studies of Ilex opaca. Contr. Boyce Thompson Inst. Pl. Res. 14: 405-10.
  • Basinger, M. A. 1999. Notes on some naturalized woody plant species new to Illinois. Trans. Illinois State Acad. Sci. 92: 32-36.
  • Bicknell, E. P. 1918. Ilex verticillata. Addisonia 3: 71-2.
  • Bicknell, E. P. 1912. The ferns and flowering plants of Nantucket - X. Bull. Torrey Bot. Club 39: 415-28.
  • Brewer, J. S. 1998. Patterns of plant species richness in a wet slash-pine (Pinus elliottii) savanna. J. Torrey Bot. Soc. 125: 216-224.
  • Britton, Nathaniel L. 1890. New or noteworthy North American phanerogams. III. Bull. Torrey Bot. Club 17: 310-6.
  • Brizicky, George K. 1964. The genera of Celastrales in the southeastern United States. J. Arnold Arbor. 45: 206-234.
  • Cador, L. 1900. Anatomische Untersuchung der Mateblõtter unter Berucksichtigung ihres Gehaltes an Thein. Bot. Centralbl. 84: 241-51, 275-83, 309-15, 340-5, 369-74. (In German)
  • Carr, D. E. 1991. Sexual dimorphism and fruit production in dioecious understory tree, Ilex opaca Ait. Oecologia 85: 381-8.
  • Carr, D. E. 1992. The relationship between crop size and fruit removal and its implication for the evolution of dioecy. Canad. J. Bot. 70: 1784-9.
  • Carr, D. E. 1990. The reproductive ecology of a dioecious understory tree, Ilex opaca Ait. Ph.D. Dissertation University of Maryland, College Park, MD,
  • Cavigelli, M.; Poulos, M.; Lacey, E. P. 1986. Sexual dimorphism in a temperate dioecious tree, Ilex montana (Aquifoliaceae). Amer. Midl. Naturalist 115: 397-406.
  • Clark, R. B.; Orton, E. R. 1967. Sex ratio in Ilex opaca Ait. Hortscience 2: 115.
  • Clark, R. C. 1991. Winterberry holly (Ilex verticillata). Morton Arbor. Quart. 27: 42-8.
  • Clute, W. N. 1898. Yellow-berry holly. Meehans' Monthly 8: 184.
  • Coladoanto, M. 1991. Ilex opaca. ()
  • Coladoanto, M. 1991. Ilex glabra. ()
  • Connors, C. H. 1954. Parthenocarpy in holly. Proc. Holly Soc. Amer. 63: 453-6.
  • Cuenoud, P. 2000. Molecular phylogeny and biogeography of the genus Ilex L. (Aquifoliaceae). Ann. Bot. 85: 111-122.
  • Decker, S. R. 1991. Nutritional evaluation of winter foods of wild turkeys. Canad. J. Zoology 69: 2128-2132.
  • Del Pero Martinez, M. A.; Pelotto, J. P.; Basualdo, N. 1997. Distribution of flavonoid aglycones in Ilex species (Aquifoliacaeae). Biochem. Syst. Ecol. 25: 619-22.
  • Dengler, H. W. 1957. Handbook of hollies. Natl. Hort. Mag. 36: 1-193.
  • Dirr, M. A.; Alexander, J. H. 1991. Ilex glabra, the inkberry holly. Arnoldia (Jamaica Plain) 51: 16-22.
  • Dudley, T. R. 1986. The story of hollies. Part 1: Diversity and history. Holly Soc. J. 4: 1-5.
  • Eberwine, M.; Dirr, M. A. 1979. Salt tolerance of hollies. Holly Letter 63: 4-6.
  • Edwin, G. 1957. Notes on Ilex. Rhodora 59: 20-3.
  • Fernald, M. L. 1939. New species, varieties and transfers. Rhodora 41: 423-61.
  • Fogg, J. M. Jr. 1960. The deciduous hollies. Morris Arbor. Bull. 11: 59-63.
  • Frierson, J. L. 1961. Some chromosome counts in the hollies. Proc. Holly Soc. Amer. 30: 5.
  • Galle, F. C. 1997. Hollies. The Genus Ilex. Timber Press, Portland, OR. , 621 pages.
  • Gargiullo, M. B. 1991. The role of secondary metabolites in over-wintering, bird-dispersed fruits of Ilex opaca and Ilex verticillata. Ph.D. Dissertation Rutgers, Univ., New Brunswick, NJ,
  • Gargiullo, M. B.; Stiles, E. W. 1991. Chemical and nutritional differences between two bird-dispersed fruits: Ilex opaca and Ilex verticillata. J. Chem. Ecol. 17: 1091-106.
  • Gargiullo, M. B.; Stiles, E. W. 1993. Development of secondary metabolites in the fruit pulp of Ilex opaca and Ilex verticillata. Bull. Torrey Bot. Club 120: 423-30.
  • Gehnrich, H. 1988. Growing hollies on Long Island. Holly Soc. J. 6: 2-4.
  • Goi, M. 1985. Seed propagation of Ilex species native to Japan. 1. Ilex crenata. Kagawa Daigaku Nogakubu Gakujutsu Hokoku 36: 95-100. (In Japanese)
  • Guba, E. F.; Stevenson, J. A. 1963. Fungus and nematode inhabitants and diseases of holly (Ilex). Exp. Sta. Coll. Agr. Univ. Mass. Bull. 530.
  • Hall, B. A. 1947. The floral anatomy of the Aceraceae and some related families. Ph.D. Dissertation Cornell Univ., Ithaca, NY25 plates + 82 p.
  • Hamilton, C. C. 1959. Insect pests of holly. Bull. Holly Soc. Amer. 2(revised): 1-21.
  • Hanna, W. J.; Grant, C. L. 1962. Spectrochemical analysis of the foliage of certain trees and ornamentals for 23 elements. Bull. Torrey Bot. Club 89: 293-302.
  • Herr, J. M. 1959. The development of the ovule and megagametophyte in the genus Ilex L. J. Elisha Mitchell Sci. Soc. 75: 107-28.
  • Herr, J. M. 1961. Endosperm development and associated ovule modification in the genus Ilex L. J. Elisha Mitchell Sci. Soc. 77: 26-32.
  • Herr, J. M. 1962. Maturation of the embryo in Ilex crenata Thunb. (Abstr.). ASB Bull. 9: 32-3.
  • Hervey, E. W. 1900. Yellow-fruited Ilex verticilata. Rhodora 2: 242.
  • Holly Society of America 1976. Holly and air pollution. Bull. Holly Soc. Amer. 14
  • Holm, T. 1929. Anatomy of certain species of Ilex of the sections Aquifolium and Prinos. Amer. J. Sci. 18: 497-504.
  • Hume, H. H. 1947. Evergreen hollies native in the United States. Natl. Hort. Mag. 26(3): 143-79.
  • Hume, H. H. 1959. Holly pyrenes (seeds). Bull. Holly Soc. Amer. 10: 1-16.
  • Ishikura, N. 1971. Anthocyanin pattern in the genera Ilex and Euonymus. Phytochemistry 10: 2513-2517.
  • Ives, S. A. 1923. Maturation and germination of seeds of Ilex opaca. Bot. Gaz. 76: 60-77.
  • Jones, R. L. 1985. The Aquifoliaceae of Kentucky. Trans. Kentucky Acad. Sci. 46: 104-107.
  • Knapp, A. K.; Carter, G. A. 1998. Variability in leaf optical properties among 26 species from a broad range of habitats. Amer. J. Bot. 85: 940-946.
  • Knowlton, C. H. 1914. New England distribution of Ilex opaca and Ilex glabra. Rhodora 16: 163-5.
  • Kreuger, B.; Potter, D. A. 1994. Changes in saponins and tannins in ripening holly fruits and effects of fruit consumption on nonadapted insect herbivores. Amer. Midl. Naturalist 132: 183-91.
  • Krischik, V.; McCloud, E. S.; Davidson, J. A. 1989. Selective avoidance by vertebrate frugivores of green holly berries infested with a Cecidomyiid fly (Diptera: Cecidomyiidae). Amer. Midl. Naturalist 121: 350-4.
  • Loesener, T. 1890. Vorstudien zu einer Monographie der Aquifoliaceen. Ph.D. Inaug. Diss. Berlin45 p. (In German)
  • Loesener, T. 1901. Monographia Aquifoliacearum. Abh. Kaiserl. Leop.-Carol. Deutschen Akademie Naturforscher, Halle, Germany. (In German)
  • Loesner, T. 1919. Uber die Aquifoliaceen, besonders uber Ilex. Mitt. Deutsch. Dendrol. Ges. 28: 1-66. (In German)
  • Loizeau, P. A. 2005. Towards an understanding of the distribution of Ilex L. (Aquifoliaceae) on a World-wide scale. Kongel. Danske Vidensk. Selsk. Biol. Skrifter 55: 501-520.
  • Loizeau, P. A.; Spichiger, R. 1992. Proposal of a classification of the inflorescences of Ilex L. (Aquifoliaceae). Candollea 47: 97-112. (In French; English summary)
  • Manen, J. F.; Boulter, M. C.; Naciri-Graven, Y. 2002. The complex history of the genus Ilex L. (Aquifoliaceae): evidence from the comparison of plastid and nuclear DNA sequences and from fossil data. Pl. Syst. Evol. 235: 79-98.
  • Martin, W. L.; Sharik, T. L.; Oderwald, R. G.; Smith, D. W. 1982. Phytomass: structural relationships for woody plant species in the understory of an Appalachian oak forest. Canad. J. Bot. 60: 1923-7.
  • McCarthy, S. 1979. Natives: Ilex verticillata L. (Winterberry, black alder, swamp holly). Arbor. News Univ. Wisconsin 28(1): 5-6.
  • McIninch, S. M.; Garbisch, E. W.; Biggs, D. 1994. The benefits of wet-acclimating woody wetland plant species. Wetland Journal 6: 19-23.
  • McMenamin, J. P. 1942. Observations on the stomatal structure of Ilex opaca. Proc. Indiana Acad. Sci. 52: 58-61.
  • McPherson, J. M. 1987. A field study of winter fruit preferences of Cedar Waxwings. Condor 89: 293-306.
  • Mehrhoff, L. J. 1985. Notes on Connecticut flora- IV. The hollies (Aquifoliaceae) of Connecticut. Newsletter Conn. Bot. Soc. 13(4): 1, 3-5.
  • Meiners, S. J.; Stiles, E. W. 1997. Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70.
  • Obeso, J. R. 1996. Fruit and seed production in European holly, Ilex aquifolium L. (Aquifoliaceae). Anales Jard. Bot. Madrid 54: 533-9. (In Spanish; English summary)
  • Paratley, R. D. 1986. Vegetation-environment relations in a conifer swamp in central New York. J. Torrey Bot. Soc. 113: 357-371.
  • Pennington, M. T. 1953. A comparative study of wood anatomy of fifty four species of the family Aquifoliaceae. Ph.D. Dissertation Univ. Virginia, (Ser. Publ. 7981)
  • Petrides, G. A. 1942. Ilex opaca as a late winter food for birds. Auk 59: 581.
  • Pettit, E. 1977. List of the largest trees of Ilex opaca in the U.S. Holly Letter 58: 10-2.
  • Philpott, J. 1956. Blade tissue organization of foliage leaves of some Carolina shrub-bog species as compared with their Appalachian Mountain affinities. Bot. Gaz. 118(2): 88-105.
  • Potter, D. A.; Kimmerer, T. W. 1989. Inhibition of herbivory on young holly leaves: evidence for the defensive role of saponins. Oecologia 78: 322-9.
  • Potter, D. A.; Kimmerer, T. W. 1986. Seasonal allocation of defense investment in Ilex opaca Aiton and constraints on a specialist leafminer. Oecologia 69: 217-24.
  • Potter, D. A.; Kimmerer, T. W. 1988. Do holly leaf spines really deter herbivory? Oecologia 75: 216-21.
  • Rathcke, B. 1988. Interactions for pollination among coflowering shrubs. Ecology 69: 446-57.
  • Roberts, A. N.; Boller, C. A. 1948. Pollination requirements of English holly, Ilex aquifolium. Proc. Amer. Soc. Hort. Sci. 52: 501-9.
  • Roberts, S. W.; Knoerr, K. R.; Strain, B. R. 1979. Comparative field water relations of four co-occurring forest tree species. Canad. J. Bot. 57: 1876-82.
  • Robinson, B. L. 1900. Variations of Ilex verticillata. Rhodora 2: 104-6.
  • Rodrigues, T. D.; Johnson, P. N.; Jeffrey, L. P. 1984. Hollyberry ingestion. Case report. Vet. Hum. Toxicol. 26: 157-8.
  • Rypma, R. B. 1989. Are black walnut trees poisonous to holly? Holly Soc. J. 7: 4-14.
  • Sargent, C. S. 1891. Ilex laevigata. Gard. & Forest 4: 220-1.
  • Sargent, C. S. 1891. Ilex. Silva N. Am. 1: 103-16.
  • Stalter, R. 1979. Some ecological observations on an Ilex forest, Sandy Hook, New Jersey. Castanea 44: 202-7.
  • Stalter, R. 1980. Some observations of American holly, Ilex opaca Aiton on the east coast of the U.S. Proc. Holly Soc. Amer. 57: 2-3.
  • Stalter, R. 1979. The Ilex opaca Ait. community of the Fire Island National seashore. Holly Lett. 64: 7-8.
  • Stalter, R.; Kincaid, D. T. 1985. Ilex opaca on Fire Island: water relations in winter at the Sunken Forest. Holly Soc. J. 3: 1-13.
  • Stalter, R.; O'Connor, D. 1984. Ecological observations on Ilex opaca. Holly Soc. J. 2: 1-10.
  • Stucky, J. M.; Patti, H. D. 1999. Regression equations for estimating Ilex opaca biomass components. Castanea 64: 350-354.
  • Supnick, M. 1983. On the function of leaf spines in Ilex opaca. Bull. Torrey Bot. Club 110: 228-30.
  • Supnick, M. 1985. The mean inner radius of sun and shade Ilex opaca leaves. Amer. J. Bot. 72(9): 1490-1.
  • Thomson, B. F. 1955. Bibliography on holly. Bull. Holly Soc. Amer. 8: 1-36.
  • Tryon, E. H. 1949. Color comparison of leaves of open and shade grown holly. Castanea 14: 117-26.
  • Tryon, E. H.; Pease, R. W. 1953. Shading effects of natural canopies on holly characteristics. Castanea 18: 70-83.
  • Vozzo, J. A.; Hacskaylo, E. 1964. Anatomy of mycorrhizae of selected eastern forest trees. Bull. Torrey Bot. Club 91: 378-387.
  • Weatherby, C. A. 1921. A form of Ilex opaca. Rhodora 23: 118-9.
  • West, L. G.; McLaughlin, J. L.; Eisenbeiss, G. K. 1977. Saponins and triterpenes from Ilex opaca. Phytochemistry 16: 1846-7.
  • Willis, O. R. 1881. Note on Ilex opaca. Bull. Torrey Bot. Club 8: 128.
  • Wilson, B. F. 1998. Branches versus stems in woody plants: control of branch diameter growth and angle. Canad. J. Bot. 76: 1852-1856.
  • Wyman, D. 1960. Ilex crenata and its varieties. Arnoldia (Jamaica Plain) 20: 41-6.
  • Young, D. R. 1985. Crown architecture, light interception, and stomatal conductance patterns for sympatric deciduous and evergreen species in a forest understory. Canad. J. Bot. 63: 2425-9.
  • Zimmermann, M. H.; Jeje, A. A. 1981. Vessel-length distribution in stems of some American woody plants. Canad. J. Bot. 59: 1882-1892.