Hypericum perforatum, known as perforate St John's-wort, common Saint John's wort and St John's wort, is a flowering plant in the family Hypericaceae.
St. John's wort is a low to medium-sized native shrub. The bright yellow flowers with a profusion of yellow stamens look like fireworks.
St. John’s wort (sometimes commonly called perforate St. John's wort, goatweed or Klamath weed) is an upright, many-branched, stoloniferous, yellow-flowered, herbaceous perennial (some say perennial weed) that is native to Europe, western Asia and northern Africa.
Plants were first brought to North America by settlers in 1696, and have naturalized over time throughout much of the continent. In Missouri, this species is now found in scattered locations throughout the State primarily in fields, waste ground, pastures, railroad right-of-ways and along roads (Steyermark). It typically grows from a woody, branched rootstock to 1-3’ tall, and features a showy display of star-shaped, yellow flowers (1 1/2” diameter) that bloom in pyramidal compound cymes in summer (June-August). Each flower has 5 yellow petals peppered with black dots, a pistil with 3 styles and a center boss of bushy yellow stamens. Stem-clasping, elliptic to oblong leaves to (1 1/4” long) have translucent dots and black marginal punctations. Foliage has an unpleasant aroma when bruised or rubbed.