Location of St. John's Wort

Worldwide there are about 350 species of hypericum, including 25 species in North
America. (29) Its native habitat is Europe, West Asia, North Africa, Madeira and the Azores, in all but the most northerly parts, with naturalized growth in Australia and North America. (30) Early settlers brought St. John’s Wort onto American soil for its medicinal and spiritual properties. By 1793, the first recorded specimen, grown without cultivation, was collected in Pennsylvania. (31) St. John’s Wort made a significant mark on the northwest corner of the United States, covering more than 2.34 million acres of ranchland in northern California. (32) Traditional herbicides were used to stop its unceasing advancement, but to no avail. Because of its toxicity to animals due to over consumption, St. John’s Wort quickly became a troublesome plant which needed to be eliminated, or at the very least kept under tight control.

In 1946, an Australian beetle, Chrysolina quadregemina Rossi, was introduced into the Pacific Northwest as a type of biological control. This particular beetle possessed a voracious appetite for the herb, and within ten years wild St. John’s Wort was reduced to one percent of its previous prevalence in that area. (33) Although this action was perceived as necessary at the time, the deliberate introduction of these beetles into the United States now carries the potential to complicate the cultivation of St. John’s Wort as a cash crop in parts of America.

When trying to identify St. John’s Wort, several unique markings should be noted: two longitudinal lines or ridges can be found along the edge of the stem which make it appear to be pressed flat (34) and, when squeezed, the bright yellow flower petals will “bleed” a reddish-purple liquid which stains the fingers. These tell-tale markers are usually enough to distinguish hypericum perforatum from other related species. The leaves appear to have translucent freckles or holes while the sepals or petals are riddled with tiny black dots. It is these dots that secrete the distinctive red liquid when crushed. (35)

St. John’s Wort is a perennial shrub which doesn’t draw much attention. It grows freely in stands and seems to blend in with other native weeds nearby. This branchy plant grows to a height of one to three feet. Its spotted leaves are pale-green and spade-like, sparsely covering its multi-branched stems. While in bloom, St. John’s Wort is striking when looked at closely, due to the variety of textures it hosts. (36)

This hardy perennial is fond of sun-exposed slopes and grows in dry grassland, pastures, sparse woods and along roadways. In America, it is not uncommon to find St. John’s Wort growing peacefully along the busy freeways or as a small, tangled hedge in the center median. It can be found in almost any type of terrain whether formally invited or not. Although not entirely true, this resilient plant is often called a weed because it can quickly take over recently disturbed open space such as mountainous hillsides, which have been clear-cut, or freshly graded soil found in an urban subdivision. (37) Today the plant can be found in most states except for those with extreme winter temperatures.

There is a continued need for organic or wild-crafted St. John’s Wort in order to meet the current demand. In some areas due to the natural abundance of the plant, cultivating St. John’s Wort as a crop is not a difficult task. In Montana, St. John’s Wort covers approximately 500,000 acres. (38) Care must be exercised, however, if trying to remove this stout plant from a specific
piece of land. Hand pulling just once will often stimulate additional growth through its horizontal runners, so close attention must be paid to dig up all roots. This can take several years, as the plant will continue to re-seed in the turned-up soil.