Photos by: Carrie J. Laird and Charles Clark
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).
|
|
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 |
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
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.