Eastern Wahoo is a low branching shrub that can reach 20 feet in height under good conditions but is usually around 6 feet.
The bark is greenish-brown to somewhat reddish brown and shows signs of shallow vertical splits on thicker stems. Young twigs may exhibit a more square shape as shown below; this is typical of other members of the Euonymus genus.
The leaves are opposite, oblong or elliptical, pointed at the tip, tapered at the base to a stalk, and finely toothed.
The inflorescence consists of small branched clusters (cymes of 5 to 15 flowers) that spring from the leaf axils.
The flowers, in late spring, are very small (1/3 inch) 4-parted flowers that have dark purple petals that have obtuse tips and a truncate base. The flowers are bisexual and have 4 stubby stamens with yellowish filaments and more whitish anthers. These rise between the petals from a purplish spongy 4-sided necrary at the base of the petals. In the center the ovary is embedded in the nectary with a style that is pale and blunt tipped. The calyx of the flower is miniscule with 4 sepals, much smaller than the petals but similar in shape and placed between the petals. While green initially, they are the same color as the petals at flower maturity.
Seed: Fertile flowers mature into a startling red, smooth capsule of 3 to 4 lobes, about 1/2 inch wide, that splits open to show dark red seeds which are 5–7 × 4–5 mm. The seeds are considered poisonous to animals and in humans they are strongly emetic and purgative.
Habitat: Eastern Wahoo grows in moist woods and thickets and requires full to at least half day sun for flowering. The root system is fibrous with a taproot.
Names: Wahoo is a Native American name. It is named 'eastern' to separate the species from the 'western' species, Euonymus occidentalis, found on the west coast, a species that has 5 petals and sepals and capsules that are not bright red. The genus Euonymus is derived from an ancient Greek name euonymon dendron, which is Latinized into euonymus which had the strange meaning 'of good name' when applied to this genus. The species atropurpureus, means 'dark purple' - the flower color. The author name for the plant classification - ‘Jacq.’ is for Nikolaus Joseph von Jacquin (1727-1817), Dutch botanist who became Professor of Botany and Chemistry at the University of Vienna where he was also director of the botanical gardens.
Comparisons: There have been two named varieties of the plant - var. cheatumii and var. atropurpurea, the latter used to be considered native to this area and much of eastern North America, and the former only to Texas. However recent scientific work has put the two together. Neither the U of M nor the MN DNR distinguish varieties any longer and Flora of North America has done away with var. atropurpurea. No other shrub in our area has purple flowers and cardinal red fruit.
Above: 1st photo - Purple 4-parted flowers in a typical branching cluster. 2nd photo - The flowering stem. 3rd photo - The reddish-gray bark of a mature stem showing typical vertical splits.
Below: 1st photo - Early spring growth on a young stem with a typical sharp-pointed but at top. 2nd photo - New leaves developing in early spring. The fine serrated edge already visible. Note the square shape of the twig. 3rd photo - Younger stems show a greenish color to the bark.
Below: The opposite leaves are pointed and finely toothed.
Below: The flowers have 4 wedge shaped petals and 4 much smaller sepals. The center of the flower has a spongy nectary structure that the 4 stamens rise from and in which the ovary is embedded.
Below: In July the lobed seed capsules have formed and as autumn approaches they begin the transition to a red color, finally reaching the brilliant red of late September - early October prior to splitting open.
Below right: The bright red seeds emerging from the capsule.
Below: The root system is fibrous with a taproot. The plant provides bright fall leaf color also.
Notes: Eloise Butler first planted this species in May 1907 with specimens she brought in from the “government reservation” (which is the area of and around Fort Snelling south of Minneapolis). She planted more in 1909, '12, '13 and 1914 and Martha Crone planted it in 1935, '40 and '49. She listed it on her 1951 Garden census under the alternative common name "Burning Bush". It is native to Minnesota and found in a number of counties in the southern 1/2 of the state from Stearns and Anoka southward, with a number of exceptions in the SW Quadrant. It's range in North America is the eastern 2/3rds of the U.S., westward as far as the Dakotas and Montana. In Canada it is found from Ontario eastward.
Martha Crone wrote in The Fringed Gentian™, Autumn 1961, how "after the foliage dries, the red seed capsules are displayed, each seed coated with the red of the Cardinal Flower - a color used on no other fruit or flower [in the eastern half of the United States]. These capsules are the size of burst popcorn and in the shape of 4-cornered hats, appearing in masses."
Uses: The wood is hard and workable. Mrs. Grieve (Ref. 7) reports that in old herbals the plant is referred to as "Skewerwood" referencing its old use in making skewers, spindles and toothpicks.
Lore: There is herbal medicine literature on the plant. The root bark, which is bitter and unpleasant to the taste, was used to create a decoction by boiling a small teaspoonful in 2 cups of boiling water and when cooled down is taken for disorders of the liver. (Ref 12). Root bark is sometimes called "Wahoo Bark" and when dry has a faint odor of licorice, and the principle is a bitter resin called Euonymin, which is available commercially as a powdered extract. In small doses it is an appetite stimulant, it larger doses it is a purgative. (Ref. 7).
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"