Common St. John's wort
Hypericum perforatum
Common St. John's wort is a perennial herbaceous plant known for its bright yellow flowers and perforated-looking leaves. It typically grows in sunny locations like meadows, forest edges, and roadsides, reaching heights of up to 100 cm. The plant contains hypericin, which stains fingers red when flowers are crushed. It is widely recognized for its medicinal properties, particularly as a natural treatment for mild to moderate depression.
Details
Habitat function
Serves as larval habitat for various insect species and structures dry grassland communities.
Food source for
Wild bees, hoverflies, leaf beetles, and caterpillars of the Treble-bar moth.
Human use
Used as an antidepressant, for wound healing (St. John's oil), in cosmetics and traditional medicine.
Ecology
Ecological role
Important food plant for specialized insects and a pioneer species in open land habitats.
Natural predators
St. John's wort beetle (Chrysolina varians), various specialized moth larvae.
Competitor species
Competitive grasses and tall perennials under increasing eutrophication of the sites.
Ecosystem service
Provision of nectar and pollen for pollinators, medicinal compounds for pharmacy.
Threats
Intensification of grassland use, herbicide application, and over-fertilization of the landscape.
Scientific profile
Profile
Reproduction
Generative via seeds (high seed production up to 100,000 per plant) and vegetative via creeping root sprouts.
Protection & threats
Main threats
Agricultural intensification (fertilization), abandonment of extensive grazing (encroachment of scrub), and herbicide use.