ST. JOHN'S WORT

St. John's Wort

St. John's Wort

Introduction

The name St. John's wort apparently refers to John the Baptist, as the plant blooms around the time of the feast of St. John the Baptist in late June. St John's wort (hypericum perforatum) is a perennial herb with a yellow flower that has been used to treat nervous conditions since ancient Greek times. Today, it is a popular herbal remedy for mild depression. The plant has many chemical compounds, some of which are believed to help depression by preventing nerve cells in the brain from reabsorbing the chemical messenger serotonin, or by reducing levels of a protein involved in the body's immune system functioning. Most preparations have been standardised to include the main active ingredients of hypericin and hyperforin.(Bausell, 2010)

It's important to note that, while St John's wort is an herb, it is still an active treatment that has specific chemical effects.

The use of St John's wort as a treatment for depression has created some controversy, with clinical trials into its safety and effectiveness constantly under review. Generally, St John's wort is well tolerated when taken on its own. The most common side-effects reported are dry mouth, dizziness, increased sensitivity to sunlight (photosensitivity), gastrointestinal symptoms and fatigue. Its safety in pregnancy has not been clarified(Sheldon, 2001). 

Common Names—St. John's wort, hypericum, Klamath weed, goatweed

Latin Name—Hypericum perforatum

Scientific Classification

Kingdom:Plantae

Order:Malpighiale

Family:Hypericaceae

Genus:Hypericum

Species:H. perforatum

Binomial name: Hypericum perforatum

Biology

This native perennial wildflower is abundantly branched and 2-4' tall. The lower stems are woody with shredded gray-brown bark, while the upper stems are green and slightly winged on opposite sides. The opposite leaves are up to 3" and ¾" across (usually about one-half this size); they are linear-oblong to oblong-elliptic in shape, smooth along their margins, and hairless. The upper surfaces of the leaves are medium green, while their lower surfaces are pale green; they are sessile or taper to short petioles. The upper stems terminate in small clusters of 3-7 flowers; additional clusters of flowers may appear along the 2 upper pairs of opposite leaves. Each flower is ½-1" across, consisting of 5 yellow petals, 5 green sepals, a pistil with 3 united styles, and abundant stamens. The petals are much larger than the sepals(Bames, 2007).

Its flowers measure up to 2.5 cm across, has five petals, and is colored bright yellow with conspicuous black dots. The flowers appear in broad cymes at the ends of the upper branches, between late spring and early to mid summer. The sepals are pointed, with glandular dots in the tissue. There are many stamens, which are united at the base into three bundles. When flower buds (not the flowers themselves) or seed pods are crushed, a reddish/purple liquid is produced.

The flowers are cross-pollinated primarily by bumblebees, which collect pollen for their larvae. Other insect visitors that seek pollen from the flowers include Syrphid flies and Halictid bees, but they are less effective at cross-pollination. Sometimes butterflies and wasps land on the flowers, but they are vainly seeking nectar -- the flowers offer only pollen from the ...