European alder buckthorn
FULL SCIENTIFIC NAME
Frangula alnus Mill.
FAMILY NAME COMMON
FAMILY SCIENTIFIC NAME
Close-up of flowers and fruits
Close-up of pinnately veined leaves
Synonyms: Rhamnus frangula L.
Frangula alnus is a deciduous small tree or coarse shrub that grows up to 6 m (19.7 ft.) tall. It is often confused with Rhamnus cathartica (see similar species below). The young branchlets are pubescent. The short oblong to obovate leaves are 3-7 cm (1-2.5 in.) long and are arranged alternately. They are dark green (in the summer) and shining above, and glabrous or slightly pubescent beneath. The leaves turn greenish-yellow to yellow in the fall, and remain on the plant when most other species have already lost their leaves. The yellow-green flowers of Frangula alnus are bisexual and 5-merous, and arranged in 1-8 flowered sessile, glabrous umbels. This plant flowers after the leaves expand, from May to September . The fruit are globose drupes, changing from red to black, and are 0.6 cm (0.25 in.) across. They ripen from July to August. It is important to note that at any given time there can be flowers, partially ripened fruits (red) and fully ripened fruits (black) present on the same plant. Page References Bailey 645, Crow & Hellquist 243, Gleason & Cronquist 341, Holmgren 321, Magee & Ahles 724. See reference section below for full citations.
Rhamnus cathartica L. (Common buckthorn)
The fruit of Frangula alnus are most often dispersed by birds.
Frangula alnus is native to Europe, North Africa and Central Asia. In the United States, this plant is present from Maine south to Pennsylvania and New Jersey, west to Michigan, Illinois, Indiana, North and South Dakota, Minnesota and Wisconsin. It is present in all New England states.
HISTORY OF INTRODUCTION IN NEW ENGLAND
Like Rhamnus cathartica, this plant was introduced to the United States before 1800 and started to invade native habitats probably around the early 1900s. In Gray's Manual of Botany (8th edition), the plant is described as "recently and rapidly spreading; likely to become obnoxious."
HABITATS IN NEW ENGLANDAbandoned Field,Early Successional Forest,Edge,Floodplain Forest,Forest Wetland,Pasture,Planted Forest,Roadside,Shrub Wetland,Vacant Lot,Wet Meadow,Yard or Garden
This plant tolerates more moisture and requires more light than R. cathartica, and can be found in swamps, fens and the edges of bogs. It also can be present in upland habitats such as woodland edges, fencerows and old fields.
Frangula alnus is a great threat to wetlands, where it can form dense stands that cause the growth of other species to be suppressed. It is readily dispersed by birds, and the extended productivity of the fruits allows it to be dispersed throughout the summer and fall. It is also an alternative host to crown rust fungi that infects oats.
Illinois Natural History Survey
General description and management guidelines
Documentation required: Specific photograph or snippet of the branch with flowers or fruits and the leaves.
Best time for documentation: Summer, fall.
Integrated Taxonomic Information System
Taxonomic information about the species
Shows distribution information as well as having additional links.
The Nature Conservancy
Extensive description and control information
Maine Invasive Plants, University of Maine
General information and photographs
Bailey, L. H. 1949. Manual of Cultivated Plants. Macmillan, New York. Catling, P.M. and Z.S. Porebski. 1994. The history of invasion and current status of glossy buckthorn, Rhamnus frangula, in Southern Ontario. Canadian Field Naturalist 108 (3): 305-310. Crow, G.E. and C.B. Hellquist. 2000. Aquatic and Wetland Plants of Northeastern North America. Vol #1. University of Wisconsin Press, Madison. Dirr, M.A. 1983. Manual of Woody Landscape Plants. Stipes Publishing Company, Champaign, Illinois. Fernald, M.L. 1950. Gray's Manual of Botany 8th edition. American Book Company, New York. Fire Conference 2000. Proceedings of the Invasive Species Workshop: The Role of Fire in the Control and Spread of Invasive Species. The First National Congress on Fire Ecology, Prevention, and Management. Tall Timbers Research Station, Miscellaneous Publication No. 11. Gleason, H.A. and A.C. Cronquist. 1991. Manual of Vascular Plants of the Northeastern United States and Adjacent Canada. 2nd ed. New York Botanical Garden, Bronx, New York. Hampe, A. and F. Bairlein. 2000. Modified dispersal-related traits in disjunct populations of bird-dispersed Frangula alnus (Rhamnaceae): a result of its Quaternary distribution shifts?. Ecography 23 (5): 603-613. Heidorn, R. 1991. Vegetation management guidelines for the exotic buckthorns: Common buckthorn (Rhamnus cathartica L.) Glossy buckthorn (Rhamnus frangula L.) Dahurian buckthorn (Rhamnus davurica pall.). Natural Areas Journal 11 (4): 216-217. Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. New York Botanical Garden, Bronx, New York. Howell, J.A. and W.H. Blackwell. 1977. The history of Rhamnus frangula (glossy buckthorn) in the Ohio flora. Castanea 42: 111-115. Magee, D.W and H.E. Ahles. 1999. Flora of the Northeast. University of Massachusetts Press, Amherst. Medan, D. 1994. Reproductive-biology of Frangula alnus (Rhamnaceae) in southern Spain. Plant Systematics And Evolution 193 (1-4): 173-186. Post, T.W., E. Mccloskey and K.F. Klick. 1989. Two-year study of fire effects on Rhamnus frangula L.. Natural Areas Journal 9 (3): 175-176. Rehder, A. 1940. Manual of Cultivated Trees and Shrubs. Macmillan, New York. Reinartz, James A. 1997. Controlling glossy buckthorn (Rhamnus frangula L.) with winter herbicide treatments of cut stumps. Natural Areas Journal 17 (1): 38-41. USDA, NRCS. 2001. The PLANTS Database, Version 3.1. (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. Wheeler, Adam R., Mark C. Starrett. June, 2001. Determining the invasive potential of Rhamnus frangula 'Asplenifolia' (cutleaf buckthorn) and Rhamnus frangula 'Columnaris' (columnar buckthorn) based on seed germination. Hortscience 36 (3): 51. White, D.J., Haber, E., and Keddy, C. (1993) Invasive plants of natural habitats in Canada. Canadian Museum of Nature, Ottawa, Ontario, Canada.