St. Johnswort (Hypericum perforatum)

Status:

Listed Noxious Weed In Montana & North Dakota

History:

First Montana Specimen Collected 1

County:

Gallatin

Year:

1905

"Worldwide there are about 350 species of Hypericum including 25 species in North America. St. Johnswort (Hypericum perforatum), also known as klamath weed or goat weed, was introduced to this country in 1696 for it's medicinal, ornamental, and "magical" properties. Today the plant is found in most states, with 500,000 acres just in Montana." (Elpel)

Habitat:

Growth Habit:

Perennial, erect, numerous branches.

Leaves:

Opposite, attached directly to stem, 1 inch long, oblong, covered with transparent dots.

Stem:

Woody at the base, 1 to 3 ft. tall, rust colored, with 2 ridges.

Flower:

Yellow, 3/4-inch diameter, in fiat-topped clusters, 5 petals with numerous stamens.

Roots:

Branched and deep, some shallow capable of sending up shoots.

Seeds:

Small, shiny black, with rough texture in a round, pointed, three-part seed pod.

Other Notes:

If you've been troubled by depression then you may be delighted to learn about St. Johnswort. St. Johnswort has become a well-known and effective herbal alternative to Prozac and other anti-depressants. These are perennial herbs with simple, opposite leaves. The leaves are often covered with dark glands or clear dots. Flower petals are usually yellow, but may be tinged with red or orange spots. At least one species has pink blossoms. The flowers are regular and bisexual with 4-5 sepals, 4-5 petals, and 10 or more stamens.

It is reported to be "cyclic" with significant population swings from year to year. St. Johnswort is a perennial plant with a horizontal spreading root system. It reproduces by both seeds and runners. A single plant may generate 15,000 to 30,000 seeds per year. Seeds remain viable in the soil for up to 10 years. Seed germination is inhibited during hot dry summers or when buried more than 2 mm below the surface." (Elpel, 15)