Multi-Institutional Acer (Maple) Collection

Arnold Arboretum of Harvard University, Boston, Massachusetts
Atlanta Botanical Garden, Atlanta, Georgia
Cornell Plantations, Ithaca, New York
Dawes Arboretum, Newark, Ohio
Hoyt Arboretum, Portland, Oregon
Morris Arboretum of the Univ of PA, Philadelphia, Pennsylvania
The Morton Arboretum, Lisle, Illinois
New York Botanical Garden, Bronx, New York
Quarryhill Botanical Garden, Glen Ellen, California
University of British Columbia Botanical Garden, Vancouver, Canada
University of WA Botanic Gardens, Seattle, Washington

Primary Focus:
Collection represents broad taxonomic diversity

145 botanical taxa and naturally occurring hybrids
2,545 accessions

Maples have horticultural and economic significance, widespread distribution and diversity. The genus Acer has been estimated to contain 238 botanical taxa and naturally occurring hybrids. No single institution can cultivate a comprehensive collection of maples, due to climatic and physical space limitations.

This multi-site collection combines the climatic variation, expertise, leadership, and physical space of 11 institutions from throughout the United States and Canada. It is the second NAPCC multi-site collection, recognized in January 2008. Current combined holdings represent about 64% of the taxa known to exist. The emphasis at each institution varies from botanical to horticultural. Some collections are of geographic focus, whereas others might support tree breeding. Yet all participating institutions are dedicated to germplasm preservation and see the benefits of working collaboratively.

Maples have posed challenges in seed and vegetative propagation; seed is best sown fresh and loses viability quickly, while grafted plants are not always vigorous or compatible with the rootstock. Conservation is a priority for several species, especially those in Asia and central Europe where they are threatened by deforestation, poor regeneration, and climate change. The invasive nature of other species deserves evaluation and rational action.

In addition to attempting to address these issues, participants are building the collection to expand represent maple diversity, and are working together to elevate curatorial standards of ex situ maple collections. A Maple Curatorial Group made up of representatives from each participating institution is undertaking these tasks.

Taxonomic References and Authorities:
Bean, W. J. (1970). Trees and shrubs hardy in the British Isles. 4th edition & suppl.. London: John Murray. 5 vols.
Delendick, T.J. (1981). A systematic review of the Aceraceae. Ph.D. Thesis, New York, NY: The City University of New York.
Dirr, M.A. (1998). Manual of Woody Landscape Plants. Champaign, IL: Stipes Publishing Co.
Ellis, W.H. (1963). Revision of Section Rubra of Acer in eastern North America, excluding Acer saccharinum L. Ph.D. Thesis, Knoxville, TN: University of Tennessee.
Jong, P.C. de, (1976). Flowering and sex expression in Acer L. A biosystematic study. Agricultural University of Wageningen, 76-2.
Flora Europea. (1998). Royal Botanic Garden, Edinburgh. URL: (05 September 2006).
Flora of China. Harvard University Herbaria. URL: (05 September 2006).
Gelderen, D.M., P.C. de Jong, & H.J. Oterdoom. (1994). Maples of the World. Portland, OR: Timber Press.
Krussmann, G. (1984-1986). Manual of cultivated broadleaved trees and shrubs. Warda, H.-D.; Daniels, G. S.; Epp, M. E., editors. [English edition]. Portland, OR: Timber Press.
Le Hardy de Beaulieu, A. (2003). An Illustrated Guide to Maples. Portland, OR: Timber Press.
Nayar, M.P. and A.R.K. Sastry. (eds). (1998). Red Data Book of Indian Plants. Calcutta, India: Botanical Survey of India.
Ogata, K. (1967). A systematic study of the Aceraceae. Bulletin of Tokyo University Forests 63: 89-206.
Ohwi, J. (1965). Flora of Japan (in English). Edited by F.G. Meyer and E.H. Walker. Washington, D.C.: Smithsonian Institution.
Oldfield, S., C. Lusty, & A. MacKinven. (1998). World List of Threatened Trees. Cambridge, UK: World Conservation Press.
Shanan, H. (1998). Rare and Precious Plants of China. Shanghai, China: Scientific & Technical Publishers.
USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: (05 September 2006)
van Gelderen, C.J. and D.M. van Gelderen. (1999). Maples for Gardens. Portland, OR: Timber Press.
Vertrees, J.D. (2001). Japanese Maples, 3rd Ed. Revised and Expanded by P. Gregory. Portland, OR: Timber Press.

2014 NAPCC Multisite Collection combined inventory

Maple Multisite Collection Coordinator:
Gregory A. Payton, Plant Records Specialist, The Dawes Arboretum, 7770 Jacksontown Rd SE, Newark, OH 43056