Aesculus
scientific name
"Buckeye"
Common name
By: Carrie Jean Laird
cjlaird@arches.uga.edu


 

Photos by: Carrie J. Laird and Charles Clark

Aesculus pavia. fruit Aesculus pavia. fruit and leaves Aesculus pavia. shrub and me
The tree illustrated above is commonly known as the red buckeye (Aesculus pavia). This particular tree was found at 126 Dearing St. at the home of Robert and Ellen Harris in Athens, GA.
 

Table of Contents
             Aesculus flava (octandra) page
           Aesculus sylvatica page  

Higher Taxon:

Family:
Hippocastanaceae
 
Description:

    The Hippocastanaceae family is composed of two genera: Aesculus and Billia (Brown nd Kirkman, 1990). The opposite palmately compound leaves with 5-11 irregularly serrated leaflets provide easy recognition of Aesculus (Duncan and Duncan, 1988). The twigs are glabrous (smooth, not rough or hairy) with terminal buds present except on those twigs that have flowers (Duncan and Duncan, 1988). The flowers are showy, coming in various colors such as white, pink, red, or yellow and appearing in large vertical branched clusters (Little, 1995). The fruit is a large, rounded brown capsule, often spiny, with a thick hard wall splitting into three parts. The fruit produces 1-3 large, rounded shiny brown seeds. There are 13 species of Aesculus with 6 being native to North America (five of these appear in Georgia, the sixth in California), 5 in Asia, 1 in India, and 1 more in North America, but introduced from eastern Europe (Little, 1995).
    The genus Billia contains two evergreen species that range from Columbia north to Mexico (Brown and Kirkman, 1988).

Species List:
 
 
Scientific Name
Common Names
1. Aesculus californica Nutt. 
 
California Buckeye
2. Aesculus flava Ait 
 
Yellow Buckeye
3. Aesculus glabra Willd. 
 
Ohio Buckeye
4. Aesculus hippocastanum L. 
 
Horse Chestnut
5. Aesculus parviflora Walt. 
 
Bottlebrush Buckeye
6. Aesculus pavia L. 
 
Red Buckeye
7. Aesculus sylvatica Bartr. 
 
Painted Buckeye, Georgia Buckeye 
     The species above are only found in North America. These are often bred to produce hybrid species.
 A more complete list of species, including hybrids, can be found at the Harvard University Herbarium web page or the  Texas A&M Herbarium web page.
 
 
Identification Guide:

I.    Buds glutinous; claw of upper petals shorter than the calyx, stamens much longer than petals;
       fruits spiny or warty                                                                           6. A. hippocastanum

I.    Buds not glutinous; claw of upper petals mostly longer than calyx, stamens longer or shorter
      than petals; fruits spiny, warty or not                                                                                   2
        2. Petals white; stamens 3-4 times the length of the petals; inflorescences
            narrow, 20-50 cm long                                                                          I. A. parviflora
        2. Petals yellow to red; stamens shorter than to twice the length of petals
            inflorescences broad, 10-25 cm long                                                                            3

            3. Petals nearly equal, pale yellow to greenish yellow; stamens about twice as long
                as petals; fruits spiny (rarely not)                                                              2. A. glabra
 
            3. Petals unequal, the upper pair longer and narrower and with a small splatulate blade,
                yellow to red; stamens shorter than to barely longer than the upper petals;
                fruits not spiny                                                                                                         4
                    4. Margin of lateral petals stipitate-glandular, stamens longer than the
                    lateral petals                                                                                            3. A. pavia
               4. Margin of lateral petals villous, without glands; stamens shorter than
                   the lateral petals                                                                                                    5
                    5. Pedicels minutely hairy to tomentose, without glands; stalk of leaflets
                        mostly over 3 mm long                                                                   4. A. sylvatica
                    5. Pedicels with small stalked gland; stalk of leaflets 3 mm long or less
                                                                                                                                   5. A. flava
 

The above key is  from Duncan and Duncan, 1988.

General Information:
 
    Economically, the genus is most important for ornamental use because of its showy blooms. However, the wood of most species is too soft for industrial use (Brown and Kirkman, 1990). The immature leaves and seeds of all species
of Aesculus produce the alkaloid aesculin which is a dangerous toxin to humans and cattle. After roasting and soaking them to remove the toxic element, the American Indians were able to make a nutritious food from the seeds. Although poisonous, some people carry a buckeye seed with them in their pocket because a common folklore still exists that a buckeye will bring the bearer good fortune.

References:
 
1. Brown, Claude L. & Katherine L. Kirkman. 1990. Trees of Georgia and Adjacent States. Timberland Press
        Portland, Oregon. ISBN 0-88192-748-3.

2. Duncan, Wilbur H. & Marion B. Duncan. 1988. Trees of the Southeast United States. University of Georgia
        Press. Athens, Ga. ISBN 0-8203-0954-0

3. Duncan, Wilbur H. & John T Kartesz. 1988. Vascular Flora of Georgia and Annotated Checklist.

4. Jones, S.B. & N.C. Coile. 1988. Distribution of the Vascular Flora of Georgia. Dept. of Botany, University
        of Georgia. Athens, GA.

5. Little, Elbert L. 1995. National Audubon Society Field Guide to North American Trees. Knopf Press. New York
        N.Y. ISBN 0-394-50760-6.

6. Radford, A.E., H.E. Ahles & C.R. Bell. 1968. Manual of the Vascular Flora of the Carolinas. University of
        North Carolina Press. Chapel Hill, NC. pp 284-285

7. Stafleu, F.A. & R.S. Cowan. 1981. Taxonomic Literature. v3. International Association for Plant Taxonomy.
         Boston, MA.