Comptonia peregrina
Common name: Sweet fern
Comptonia peregrina or sweet fern, despite its common name, is not a fern. It is a low-maintenance, mound-forming, deciduous shrub in the Bayberry family (Myricaceae). C. peregrina is native to eastern North America from Ontario, Quebec, and Nova Scotia southward to Northern Georgia. Sweet fern is adaptable to a wide range of soil condition, and tolerates drought once established. This shrub doesn't like to have its roots disturbed and so should be planted in its permanent home when young.
C. peregrina flowers are small, brown catkins that appear during April and May before the leaves unfurl. Male and female catkins may be on the same shrub. These catkins are followed by fruit which look like mini chestnuts, each containing a number of small, edible nuts. Sweet fern leaves are narrow, pinnatifid (having lobes with incisions extending halfway or more to the midrib), and glossy green. Resinous glands are found on both the upper and lower leaf surfaces. The leaves give off a sweet scent especially when crushed.
Sweet fern is a non-leguminous nitrogen fixer. It has a partnership with a bacteria that can take in nitrogen from the air and make it available to plants. Nitrogen-fixing plants are valued for their ability to improve the soil in which they grow.
Comptonia is a monotypic genus with C. peregrina being its only living species. The genus is named in honour of Reverend Henry Compton, Bishop of Oxford. He was a dendrologist and patron of botany. The species name 'peregina' means 'one that travels'. In French, its name is 'comptonie voyageuse' or 'travelling comptonia'. It's thought that the name probably refers to the plant's habit of reproducing by rhizomes to produce colonies. C. peregrina is a good plant choice for stabilizing slopes and banks and for erosion control due to its abundant underground rhizomes.
Sweet fern attracts birds, butterflies, and small mammals. It is the larval host for some species of butterflies and moths. Birds such as flickers eat the small nutlets, and grouse feed on the buds and catkins. Colonies of sweet fern provide cover for wildlife.
C. peregrina was used by Native Americans as an anti-itch remedy, to treat intestinal problems, as a mosquito repellent, and to treat other afflictions. The young leaves fresh or dried were used to make herbal tea.
Comptonia peregrina can be found in Bed 137E of the Canadian Heritage Garden.
Text and photos by Kumi Sutcliffe