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St. Johnswort
Hypericum perforatum
Adult![]() This perennial grows one to three feet tall. Stems are rust colored and woody at the base. |
Rosette![]() |
Weed Infestation![]() St. Johnswort was introduced from Europe. It invades areas with sandy or gravelly soils. Reproduction is by seeds and short runners. It contains a substance that is toxic (but rarely fatal) to white-haired animals causing them to develop skin irritations and often lose weight when exposed to sunlight. It is also a key ingredient of some popular dietary supplements. |
Flower![]() The flowers are bright yellow with five petals. |
Leaf![]() Leaves are characterized by prominent veins and transparent dots, visible when held up to light. |
Other |