Calycanthus floridus Seeds | Sweetshrub
LATIN NAME: Calycanthus floridus
COMMON NAME: Sweetshrub
Plant Profile
Calycanthus floridus is grown for a scent that is hard to describe and hard to forget. The flowers are dark maroon, about five centimetres across, with strap-shaped petals, and they smell of strawberry, of banana and of spice by turns, depending on the nose. The leaves and the bark carry the same scent when crushed, and the dried bark was hung in houses as a spice substitute.
The shrub grows to about two metres with a loose, suckering habit, and the leaves are oval, rough and mid-green, turning yellow in autumn. It is native to the woodland edges of the south-eastern United States, from Virginia to Florida, and it has been in gardens since the eighteenth century, which is why several named forms exist.
Science & Biotechnology
The scent comes from a mixture of volatile compounds in the essential oil, including linalool, geraniol and several esters, and the composition varies between plants, which is why two sweetshrubs can smell quite different. The bark and leaves also contain calycanthine, an alkaloid related to strychnine, and the plant is toxic if eaten in quantity.
The flowers are pollinated by beetles, not by bees. The maroon colour, the fermenting smell and the bowl shape are all beetle cues, and the flower traps its visitors for a day while they feed on pollen and on the inner petals. The plant is one of the few in North America with this syndrome, which it shares with magnolias and with pawpaw.
Uses & Benefits
The shrub is grown for the scent and for the shade tolerance, and it is planted near a door or a path where the flowers can be smelled. The dried bark was used as a cinnamon substitute in the southern states, hence the name Carolina allspice, though the flavour is not the same and the alkaloid makes it a poor idea.
In local medicine a decoction of the bark was used for fever and for stomach complaints, and a poultice of the leaves was applied to wounds. The plant is not used commercially, and it has no place in modern pharmacy.
Growing from Seed
Seed is short-lived and should be sown fresh in autumn. Clean it from the capsule, sow it in a moist mix, and leave the pot outdoors for the winter; germination is in spring. Suckers and cuttings are easier, and a named form must be propagated vegetatively.
The shrub wants light shade and a deep, moist soil with plenty of organic matter, and it tolerates clay better than most. It is hardy to about minus twenty and it needs little pruning, though it spreads by suckers and can form a thicket. Plant it where the scent will be caught, and keep it away from livestock, since the foliage is toxic.
Our Take
A shrub for people who garden with their nose, with a scent that depends on the individual plant. Buy it in flower, not from a description.
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