Eastern Sweetshrub Carolina Allspice Calycanthus floridus – Native Plant of the Week

Introduction

The first time I saw Carolina Allspice or Eastern Sweetshrub blooming in the forest I was thrilled. Its unique burgundy-red flowers intrigued me and I knew it was special. Calycanthus floridus is part of the Calycanthaceae family in the Laurales order of flowering plants. Laurales are neither monocots nor dicots. Instead, Laurales are one of the earliest lineages of angiosperms that evolved, part of the Magnoliids. They are a diverse clade that share some features with monocots, dicots, and even gymnosperms the naked seed plants (conifer trees etc). If you just take a look at its tepals and numerous free carpels, you can tell it is different from most other typical flowering plants. And the added bonus is that the entire plant has an amazing aroma.

Description of Eastern Sweetshrub or Carolina Allspice

Stem & Leaves

Calycanthus floridus is a deciduous shrub of the Calycanthaceae family of the Laurales order of Basal Angiosperms. It is an understorey shrub that grows to 3.5 m tall and up to 3 m wide with multiple erect branches. Its bark is reddish-brown when young then turns a light brown color with age. The bark develops numerous small horizontal lenticels. The bark itself, like the rest of the plant, is aromatic. It frequently propagates vegetatively via root suckers to produce small clonal patches of the same plant. However, it is considered non-invasive.

The leaves are arranged oppositely in pairs along the stems. They are elliptic, oblong or ovate and 5 – 15 cm long by 2 – 6 cm wide. The base of the leaves are acute to truncate. The apex of the leaves may be acute, acuminate or blunt. Margins are smooth without any teeth or lobes. The adaxial (upper) surface is green or dark green. Its abaxial surface is green or glaucous and may be glabrous or pubescent. The leaves are on 3 – 10 mm long petioles (leaf stalks) that are pubescent or glabrous. Its lateral buds are partly hidden by the base of the petioles. The leaves are deciduous and turn a golden-yellow in the fall before they drop off for the winter.

Flowers & Fruits

The aromatic flowers appear from April to July depending on latitude, aspect etc. They are solitary, reddish-brown, reddish-purple or burgundy in color. It possesses virtually identical-looking tepals rather than separate sepals and petals, similar to the monocots. It has 7 – 20 tepals that are oblong–elliptic to obovate–lanceolate. They are 20 – 40 mm long and 3 – 8 mm wide with an acute apex. The hypanthium (base or cup of the flower) is 20 – 60 mm in diameter by 10 – 30 mm high at maturity and may be cylindrical, ellipsoid, pyriform or globose when mature.

It has 10 – 20 oblong stamens. There are numerous free carpels in the center.

Its fruit is a green leathery and wrinkled urn-shaped indehiscent pseudocarp from an accessory receptacle. It is up to 8 cm long and 5 cm wide by the time it matures and turns brown in the fall. The fruit persists on the shrub all winter. Inside the fruit are numerous 1 seeded brown achenes (seeds) that are each 10 mm long by 5 mm wide.

Similar Species Frequently Confused With

The unique flowers and aroma of this plant make it hard to confuse with others. However, there is another species in the same genus and another aromatic shrub with unique red flowers in the same region that it could be confused with.

• Calycanthus occidentalis – this is the Western Sweetshrub native to the western USA. However, it is found only sporadically in the east where it was likely introduced. It is a taller shrub that grows to 4 m and its lateral buds are more exposed rather than hidden by the petiole. Its leaf bases are rounded to cordate rather than acute to truncate and its apex is rounded rather than blunt, acute or acuminate.
• Illicium floridanum – Star Anise is an evergreen shrub native to the southeastern USA. It is also very aromatic and possesses somewhat similar flowers around the same size with similar colored tepals. However, it usually possesses more tepals, from 21 – 33. It also has more stamens anywhere from 25 – 50. It produces characteristic star-shaped fruits rather than urn-shaped ones. And it retains its leaves all winter.
• Calycanthus hybrids – there are now several hybrids and cultivars grown in gardens throughout the USA but they generally are not found outside of cultivation. They also typically possess larger flowers with more tepals, and their tepals may vary more in color, depending on the cultivar.

Distribution of Eastern Sweetshrub Calycanthus floridus

Carolina Allspice is found only in the eastern USA. iNaturalist reported two locations in southern Ontario, Canada. However, both locations were on roads in residential areas so they were likely planted there rather than occurring naturally.

In the USA, Eastern Sweetshrub is found in Missouri, Illinois, Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Tennessee, Kentucky, Virginia, Washington DC, West Virginia, Ohio, Pennsylvania, Maryland, Delaware, New York, Connecticut and Massachusetts.

Habitat and Growing Conditions of Eastern Sweetshrub

Eastern Sweetshrub grows in full sun to full shade. It is common in open, mixed, and deciduous forests where it gets enough light to grow as an understory shrub. In shadier areas it will still grow but is generally taller with less width and less flowering. It also grows at forest edges and openings and on moist hillsides.

Carolina Allspice prefers moderate soil moisture levels and loamy soil. However, it will tolerate wet and clayey soil types and can even tolerate some temporary flooding. It does less well in sandy soils prone to drought but will occasionally grow there. It grows well in mildly acidic soils. Carolina Allspice will tolerate alkaline soils but will not tolerate saline soil conditions.

Growing Calycanthus floridus in Your Garden

Growing species native to your area is a great addition to your garden. Once established they require little to no maintenance of any kind. They already grow in your area without water or fertilizer, so they will easily grow in your yard if you live in their range. They provide important wildlife and biodiversity values as well.

Calycanthus floridus is a wonderful addition to your eastern garden. It is a beautiful sweet-smelling shrub with gorgeous flowers. Since it is already used as a landscape plant it should be relatively easy for you to find shrubs to plant in your yard rather than having to start them from seed. Since they will grow from seed and also spread vegetatively you could also harvest some from the wild for propagation using ethical wildcrafting principles of course. While the cultivars are lovely so are the wild varieties and they provide added biodiversity values. Or you can always grow both!

Eastern Sweetshrub plants are super easy to grow. Plant your shrubs in any well-drained soil in full sun to part shade. While they do tolerate most soil conditions they prefer a rich loam. If grown in the shade it will grow taller and a bit lankier. If you live in a particularly hot climate they will benefit from a little afternoon shade. In either case prune immediately after flowering if you want it to maintain its compact shape. Or you can let it grow to its conditions, depending on where you plant it.

Maintenance

Pruning will keep its shape if that is what you want. Also, it tends to produce root suckers so if you don’t want it to naturalize just remove the suckers as they grow. They do not grow very rapidly so once every year or two is more than sufficient maintenance.

Mulch annually every early spring with organic compost to feed it to encourage more blossoms.

Otherwise, it is a hearty plant that tolerates cold, heat, some seasonal flooding, moderate drought and even mild fires. It is virtually insect and disease-free. Deer and rabbits seldom graze on its aromatic foliage. It is a very low-maintenance and highly resistant plant that also happens to be beautiful!

Wildlife Values of Carolina Allspice

Carolina Allspice attracts numerous pollinators including bees and lots of butterflies. Beetles are also attracted to the flowers. It is a host plant for native butterflies.

Status of Calycanthus floridus

Carolina Allspice is considered Globally Secure, G5.

In the USA Calycanthus floridus is considered locally Secure S5 only in North Carolina. It is considered Vulnerable S3 just north of North Carolina in West Virginia. Sweetbush is considered Imperiled S2 in Kentucky and Florida. In Virginia it is considered Critically Imperiled S1. It is presumed to be extirpated (locally extinct) in Ohio, though I did not find information as to whether or not it was actually native there. USDA lists it as being introduced in the northern states of Illinois, Maryland, Delaware, Washington DC, Pennsylvania, and New York. In all other states where it is found it is as yet unranked.

Eastern Sweetshrub is not found in either Canada or Mexico.

Traditional or Other Uses of Eastern Sweetshrub or Carolina Allspice

Carolina Allspice as Food

The bark is fragrant and edible and is sometimes used as a substitute for cinnamon, which is where it gets the common name of Carolina Allspice from.

The petals of the flowers are sometimes used in tea. Caution is advised though as the plant contains alkaloids that could lead to heart convulsions in sensitive individuals so use in moderation.

Calycanthus floridus Medicinal Uses

The Cherokee people of the eastern US have used Calycanthus floridus in numerous medicinal applications. Resins from the bark were used on sores and wounds and used in an infusion for hives. It was frequently used as a dermatological aid for children in particular. A cold infusion of the bark was used as an eyewash for those who were losing their eyesight. A strong decoction of the roots makes a powerful emetic to induce vomiting and in milder forms it was used to treat urinary infections. An infusion of the bark was also used for urinary complaints. Occasionally all parts of the plants were used as in incense or perfume.

Herbalists today occasionally use it as an antispasmodic and disinfectant. It makes a powerful heart depressant, however, and should be used with caution.

Eastern Sweetshrub as an Ornamental

Due to its lovely fragrance and beautiful spring flowers, it is often used as an ornamental plant in gardens in borders, native plant gardens, butterfly gardens, etc. It is also occasionally used in cut flower arrangements, dried flowers and potpourri for its lovely fragrance.

Ethical Wildcrafting of Calycanthus floridus

Check the status in your state before harvesting since it is imperiled or vulnerable in several states. See above section on Status. Alternatively, grow it in your garden for its lovely leaves and flowers and its non-invasive nature.

If you are harvesting Calycanthus floridus from the wild as always use the 1 in 20 rule of Ethical Wildcrafting. Pick one in every 20 flowers, leaves or plant suckers that you see. If harvesting the bark never ring the shrub as you will kill it. The best practice for harvesting bark from a shrub with plenty of branches is to harvest a single branch from a large, healthy specimen and scrape it entirely.

Wildcrafting and Processing

Picked fruits, leaves, bark or roots can be placed in a basket, bowl or paper bag and brought home for processing. If you are harvesting multiple products on the same day be sure to label the plant parts in a paper bag so that you do not confuse different plants.

To dry the leaves or flowers simply place them on a rack or screen in a single layer and allow them to dry. Bark can be scraped off the branch and then dried the same way as flowers or leaves. Roots should be brushed clean of any dirt then chopped into more manageable pieces before drying. Dried roots are notoriously difficult to cut into smaller pieces once dried.

Once dried the leaves, flowers, bark and roots can be stored in a jar for later use. Label your jar with the species name and the date of harvest. I also usually add the location of harvest for my own reference. The potency of medicines can vary with the location so I like to know where something came from in case I find it particularly potent or weak. Do not grind or crush any plant parts until you are ready to use them to keep them as fresh as possible and preserve their medicinal properties. When you pre-grind, even if stored in glass jars, this increases the oxidation rate and rapidly degrades the medicinal properties. This renders them ineffective in a shorter amount of time than if left as whole as possible.

References and Resources

Canadensys Plant Search https://data.canadensys.net/vascan/search

Dictionary of Botanical Terms – by Lyrae’s Nature Blog https://lyraenatureblog.com/blog/dictionary-of-botanical-terms/

Eflora Plants of North America http://www.efloras.org/browse.aspx?flora_id=1

iNaturalist Plant Search https://www.inaturalist.org/home

Native American Ethnobotany http://naeb.brit.org/

Natureserve Explorer https://explorer.natureserve.org/Search

North Carolina Extension Gardener on Calycathus floridus https://plants.ces.ncsu.edu/plants/calycanthus-floridus/

USDA Plants Database https://plants.sc.egov.usda.gov/home

Wikipedia on Calycanthus floridus https://en.wikipedia.org/wiki/Calycanthus_floridus

Willis, Lyrae (2022).  Plant Families of North America.  Not yet published. 

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