American Smoketree

Basic Information
Tree ID: 
104
Family: 
Genus and species: 
Description: 
This tree is on the slope leading to Marsh Botannical Gardens. It leans downhill and gives a delicate impression with one short trunk and seven thinner trunks branching off. It has a scaly bark and blooms in June. While most American smoketrees have short trunks, this tree has an especially short trunk because it was hit by a neighboring redwood as a young tree. This fall split the trunk into eight small branches. One was shaved off in March, so now there are seven branches coming out of the trunk and its diameter at breast height is smaller.
Surveyors: 
Daisy Massey
Location
Collected Data
Tree shape: 
Oval
Date of tree entry: 
02/07/2019
Height: 
7.50 m
7.52 m
Diameter at breast height: 
1.64 m

152.00 m

Bark
Scales with ridges broken horizontally.
Twigs & branches
There are seven branches (at first there were eight, but one was shaved off in March) coming out of the trunk. From each branch, there are smaller branches, and the pattern of twigs on the branches is whorled. In February and March the twigs were mostly rachis, which is the gray deadened twig after the flower has bloomed. In April, buds were seen coming off of the now living twigs.
Foilage
In the fall, the leaves will be a dark redish-bluish color, as pictured above. The buds (and leaves) are alternate. The leaves are simple and obovate.
Reproductive Structures
The flowers really composed of inflorescences--a stem with many branchings of flowers. At the end of each flower branch is a panicle, or hair. The flowers develop at the end of the panicles at the end of May and in June. The flowers are small greenish-white and clustered monocots. The fertile flowers then turn into dark seeds and the infertile flowers disintegrate. The tree is dioecious--the male and female flowers are on different plants. The male flowers are larger and showier than the female flowers. Pollination occurs by insects.
Fruit
The fruit are small, kidney-shaped drupe that contain the seeds. Wildlife, especially finches, disperse the seeds.
Seasons
  • Summer, photographer Alber Vick from Wildflower Center Slide Library
  • Fall, from the Wasowski Collection
  • Winter
  • Spring
Research
Natural range of distribution: 
Habitat: 
Native to North America, Cotinus obovatus prefers rocky, usually mountainous soils. It grows in Kentucky, Tennessee, Alabama, and Oklahoma, with disjunct populations in central Texas. It prefers to grow at the edge of the forest and its buds are alternate so that it can get more sunlight. It does not prefer extremely wet climates.
Origin, history, and uses: 

The American smoketree was discovered in Oklahoma in 1819. It was named Cotinus obovatus in 1840 and is the only species of the genus “Cotinus” in the Western hemisphere. However, it is a close relative to Cotinus coggygria, another smoketree, which grows along the Great Wall of China. 

The American smoketree almost went extinct during the Civil War when it was harvested for to make orange and yellow dyes. Their wood was also strong enough to be used in fence posts. Two American smoketrees stand at the base of Abraham Lincoln’s tomb in Springfield, Illinois. American smoketrees were introduced into cultivation in 1880. They are not on any conservation list in 2019, but are no longer harvested for use.

Phenology: 
Green and white flowers bloom at the end of May and in June. In August, the flowers drop if they are infertile, or turn into seeds if they are fertile. The seeds are then eaten by birds or eaten by wildlife on the ground, and are dispersed throughout. In September, the leaves turn dark red or burgundy. Cotinus is decidouos, the leaves drop at the end of fall. Budding begins at the beginning of April, and leaves begin to form at the end of April.
References: 

Natural Range of Distribution map from USDA Forest Service: “Glade Top Trail #2 Smoke Tree Scene.” Mark Twain National Forest - Special Places, 2015, www.fs.usda.gov/detail/mtnf/specialplaces/?cid=fseprd514284. Accessed April 24, 2019

Photographs from Lady Bird Johnson Wildflower Center at University of Texas, “Cotinus Obovatus” https://www.wildflower.org/gallery/result.php?id_image=38108. Accessed April 24, 2019

“Cotinus Obovatus.” Plant Database Lady Bird Johnson Wildflower Center - The University of Texas at Austin, www.wildflower.org/plants/result.php?id_plant=COOB2. Accessed April 24, 2019

“Cotinus Obovatus.” Bernheim Arboretum and Research Forest, bernheim.org/learn/trees-plants/bernheim-select-urban-trees/american-smoketree/. Accessed April 24, 2019

“Cotinus Obovatus.” Plant Database Lady Bird Johnson Wildflower Center - The University of Texas at Austin, www.wildflower.org/plants/result.php?id_plant=COOB2. Accessed April 24, 2019

Gilman and Watson, “Cotinus Obovatus.” Fact Sheet ST-208, a series of the Institute of Food and Agricultural Sciences, University of Florida. Environmental Horticulture Department, Florida Cooperative Extension Service, Publication date: November 1993. http://hort.ufl.edu/database/documents/pdf/tree_fact_sheets/cotoboa.pdf Accessed April 24, 2019

Tripp, “Considering Cotinus.” Arnoldia 1994, Summer. Accessed April 24, 2019 http://www.arnoldia.arboretum.harvard.edu/pdf/articles/911.pdf

Little, “American Smoketree, One of Oklahoma’s Rarest Species.” USDA, Academy for Science, 1942. Accessed April 24, 2019 http://ojs.library.okstate.edu/osu/index.php/OAS/article/viewFile/5938/5560

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