Kinds of Herbal Plants

St. John's Wort

• St. John's wort (Hypericum perforatum) is a perennial that has been declared a noxious weed in some states. It has a deep taproot, short stems and may grow from 1 to 5 feet tall, depending on the soil conditions and available moisture. Its 1-inch leaves are sword-shaped, and the five-petaled flowers are a bright golden yellow. According to the University of Maryland Medical Center, St. John's wort is one of the most common herbs and is used to treat mild or even moderate depression. It can interfere with other medications, triggering the the United States Food and Drug Administration to issue an advisory regarding drug interactions and this herb. St. John's wort also increases skin sensitivity to sunlight, affecting grazing animals as well as consumers. Additionally, the National Center for Complementary and Alternative Medicine reported that St. John's wort is not effective for treating severe depression.

Echinacea

• Among the many varieties of echinacea, purple coneflower (Echinacea purpurea) provides most of the echinacea supplement used in the United States. This attractive, long-blooming perennial is a favorite in water-rich gardens. The flowers attract butterflies throughout the summer, while the ripening seedheads feed birds in the fall. Not only useful in the garden, echinacea extracts support the immune system, reportedly preventing colds and shortening the duration of colds, flu and other viral infections. Although many clinical trials of other herbal supplements are inconclusive, the University of Maryland reports a survey of 14 echinacea studies showed that echinacea supplements did, in fact, reduce the duration of the common cold by nearly 1 1/2 days. It also decreased the chances of getting a cold by 58 percent.

Ginko

• Ginko (Ginko biloba) is a survivor, preserved in fossil records and the last member of its family. This deciduous tree is tolerant of many growing conditions, including street-side plantings, and the fan-shaped leaves turn a bright yellow in autumn. Herbal preparations come from the foul-smelling fruit of the female tree. According to the University of Minnesota, studies show that ginko is effective in increasing circulation, improving memory and supporting cognition. Ginko supplements act as a blood thinner; always consult your doctor before taking any herbal supplement.