The Aceraceae

The Maple Family

Acer saccharum: Sugar Maple	Fall Foliage of Acer saccharum

The Aceraceae are trees and shrubs found in temperate regions around the world. Comprising 2 genera and around 120 species the Aceraceae are a dominant component of temperate deciduous forests.

Click here for a distribution map of the Aceraceae in the U.S.A.

Vegetative Characters | Reproductive Characters | Diagnostic Characters | Economic Importance/Fun Facts | Evolutionary Adaptations and Relationships | Glossary of Terms | References and Links | Pictures

Vegetative Characters

• Woody trees or shrubs
• Mainly deciduous
• Leaves opposite without stipules
• Leaves usually simple and palmately veined and lobed, pinately veined and entire or toothed in a few species, palmately or pinnately compound in even fewer species
• Plant with or without lacticifers in stems or in leaves and stems
• Stems usually with solid, tri-lacunar internodes

Reproductive Characters

• Pollination through both insects and wind
• Monoecious, dioecious, or polygamous
• Inflorescence a panicle, raceme, corymb or umbel-like axillary cluster
• Flowers perfect or imperfect, actinomorphic, hypogenous
• Sepals (4) 5 (6-9) distinct or basally connate
• Petals (4) 5 (6-9), distinct or absent
• Stamen 8 (4-12), distinct, nectary disc often present
• Carples 2 (3+), connate
• Ovary superior and 2 loculed with 2 ovules/locule
• axile placintation
• styles and stigmas 2 or 1 and deeply divided
• Fruit a samaroid schizocarp
• Seed is solitary and without endosperm
• Gynoecium is usually flattened and even in flower has two projecting wing-like protuberances

Diagnostic Characters

• Opposite exstipulate leaves
• Fruit a winged schizocarp

Economic Importance/Fun Facts

• Several species of Acer are valuble as timber trees
• Maple sugar comes from Acer saccharum
• Ornimental for shade trees and fall colors

Evolutionary Adaptations and Relationships

• Fossil plant parts are common in the Eocene
• Aceraceae and Hippocastanaceae are sustained as derived groups within the Sapindaceae
• While Sapindaceae is clearly paraphyletic it is still somewhat unclear whether Aceraceae and Hippocastanaceae are mono or paraphyletic

Glossary of Terms

• laticifers - a cell or series of fused cells containing latex
• Lacuna - cavity or gap, usually referring to one found in tissue
• Polygamous - bearing perfect and imperfect flowers on the same plant

References and Links

• Walters, D.R. and D.J. Keil, 1996. Vasccular Plant Taxonomy, Fourth Edition. Kendall/Hunt Publishing Co. Dubuque, IA 52002
• Zomlefer, Wendy B., 1994. Guide to Flowering Plant Families. The University of North Carolina Press Chapel Hill, NC USA.
• Judd, W. S., C. S. Campbell, E. A. Kellogg, P. S. Stevens. 1999. Plant Systematics: a phylogenetic approach. Sinauer Associates, Inc. Sunderland, MA U.S.A.
• http://herbarium.usu.edu/Families/Aceraceae.html
• http://botit.botany.wisc.edu/courses/systematics/family_index/Family_Pages/Aceraceae.html
• http://ag.arizona.edu/classes/rnr202/taxtour/maple.html

Pictures

Winged schizocarp	Disected flower

Leaf of Acer pltinoides	Winged schizocarp of Acer pseudoplatanus

Notice opposite leaves	Acer Campestris flower

For questions or feedback, contact: Kris Hamwi