A perennial herb with lovely yellow flowers. It is easy to grow, but take care as it is poisonous to many animals if eaten. Plant in full sun to partial shade, in soil that is well-drained, light and moist. Stands up to abuse, can take the heat of summer, and bounce back with bright yellow flowers in mid to late summer. Plant to hold the soil in place on steep slopes. The flowers are quite large considering the small size of the plant, and it can bloom over a long period of time in the summer.
Since at least the 5th century BCE, the herb has had a reputation as a wound herb. It is said that the herb was given its name from the Knights of St. John’s of Jerusalem who used it to treat wounds on the Crusades battlefields.
It is also said that it received its name from squeezing the dots on the flowers. When squeezed, the dots ooze a red pigment that is said to represent the blood of St. John the Baptist. The plant traditionally blooms by June 24, which is also associated with John the Baptist, according to the Catholic calendar.
It was believed that the herb dispelled evil spirits, and the insane were often forced to drink infusions made from the plant.
According to the Doctrine of Signatures, because the herb was yellow, it was associated with “choleric” humors and used for jaundice and hysteria.
Old herbals often refer to Tutsan (H. androsaemum) from the French toutsain, or heal-all, which was also used to treat injuries and inflammations.
Although it fell into disuse in the 19th century, it has recently regained prominence as an extremely valuable remedy for nervous problems.
Used for hundreds of years by the Klamath, Nez Perce, Umatilla, Yakima, and other Native American tribes, this herb has a calming effect on the nerves, but is also considered a stimulant by some herbalists.
Dioscorides, Paul of Aegina, Pliny, Galen have all referred to the plant as one that relieves excessive pain, removes the effects of shock, and has a tonic effect on the mind and body. As such, it is especially valuable for post-surgical pain.
When it arrived in the New World, it quickly took over vast tracts of land, especially in the Pacific Northwest where it was known as the Klamath weed. Cattle loved, it but those that ate large quantities became sun-sensitive and ultimately developed severe sunburn. When herbacides failed to control its growth in 1946, an Australian beetle, that also loves the herb, was imported; and, within a decade, the weed was declared under control. As with anything introduced against nature, the beetle thrived to the point that it is now threatening commercial growths now that the herb has become popular.