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Hypericum spp. (St. John’s wort)

Plant Names Tell Their Stories: Hypericum spp. (St. John’s wort)

H. frondosum ‘Sunburst’ attracts bees, which are rewarded with pollen.
H. frondosum ‘Sunburst’ attracts bees, which are rewarded with pollen.

The genus Hypericum has a memorable etymology from the Greek: hyper, meaning “above” and eikon, meaning “image,” referring to the practice of hanging these flowers above icons. Why is the common name St. John’s wort? During medieval times, these mystical plants were burned at Midsummer’s Eve bonfires to ward off evil spirits; the fact that the flowers looked like miniature suns and bloomed at the time of the summer solstice was considered remarkable. The Christian calendar designated June 24, Midsummer, as the feast day of St. John the Baptist; thus, the association of this long-revered plant and the saint. Wort is a word applied to plants, often those historically used to cure diseases.

There are over 490 species in the genus Hypericum with a nearly world-wide distribution. The source of the St. John’s wort herbal remedy for mood disorders are the leaves and flowers of Hypericum perforatum, a Eurasian species named for the translucent dots of glandular tissue that look like perforations on the leaves.

H. patulum ‘Sungold’ has a long season of bloom and provides excellent cut flowers.
H. patulum ‘Sungold’ has a long season of bloom and provides excellent cut flowers.
H. kalmianum ‘Ames’ is a cultivar of a species native to the Great Lakes region of the USA.
H. kalmianum ‘Ames’ is a cultivar of a species native to the Great Lakes region of the USA.











The Morris Arboretum boasts six different species of this shrub that are grown for their landscape interest and support of pollinators:

  • H. frondosum ‘Sunburst’ – frondosum meaning “especially leafy”
  • H. x hidcoteense ‘Hidcote’ – hidcoteense meaning “from Hidcote,” an English town and garden
  • H. hypericoides ssp. Hypericoides – hypericoides meaning “resembling Hypericum”
  • H. kalmianum ‘Ames’ – kalmianum honoring Pier Kalm, the Finnish naturalist credited with the discovery of this species for science in North America in the 1700s
  • H. prolificum – prolificum meaning “very fruitful”
  • H. patulum ‘Sungold’– patulum meaning “spreading”

When you visit the Arboretum this summer, enjoy the sunny blooms of the various specimens of St. John’s wort. The exact locations of the shrubs can be found on Collection Connection.

P.S. for plant nomenclature nerds only: Hypericum hypericoides ssp. hypericoides is awkwardly repetitive and here’s why. In the 1700s Linnaeus named this entity Ascyrum hypericoides, meaning “Ascyrum resembling Hypericum.” When this plant was moved to the genus Hypericum, its new name became Hypericum hypericoides, meaning “hypericum resembling hypericum.” This is nonsensical but, according to the rules of botanical nomenclature, in cases of a genus change, the specific epithet remains the same (when possible; there are instances when it cannot, due to other nomenclatural rules). And when the first subspecies was described, the name Hypericum hypericoides ssp. hypericoides was automatically created, by following the rules and appropriating the specific epithet , to encompass those plants that did not have the differentiating characteristics of the other, newly described subspecies.

Katherine has her Certificate in Botany from the New York Botanical Garden and is a botanical tour guide and free-lance writer. You can contact her with comments or requests for photos at