Great St. John’s wort (Hypericum pyramidatum)

Features and Characteristics

Hypericum pyramidatum, commonly called great St. John’s wort, is an upright perennial that typically grows 2-5’ tall and features a showy display of yellow flowers (2” across) that bloom in pyramidal cymes in July-August. Each flower has 5 yellow petals, 5 styles (most hypericums have 3 styles) and a center boss of bushy yellow stamens. Stem-clasping, elliptic leaves to 5” long. Hypericum pyramidatum (considered by many to be synonymous with Hypericum ascyron) is native to streambanks and moist wooded slopes from Maine to Manitoba south to Maryland, Indiana and Kansas. In Missouri it is found in wooded slopes and thickets in several counties in the far northern and northwestern part of the state. This plant is also native to central and eastern Asia.

Genus name comes from the Greek words hyper meaning above and eikon meaning picture in reference to the practice of hanging flowers from this genus above images, pictures or windows.

Specific epithet meany pyramidal in reference to the flowers.

Plants of the genus Hypericum (some species have been used since ancient times in the treatment of wounds) were apparently gathered and burned to ward off evil spirits on the eve of St. John’s Day, thus giving rise to the genus common name of St. John’s wort.