Hypericum perforatum (Common St. John’s Wort)

Native to Europe, North Africa, and western Asia, common St. John’s wort is a perennial herb that spreads through underground stems. Opposite, stalkless leaves bear translucent dots, with darker glands sometimes marking their margins. Yellow flowers usually have five petals with scattered black dots along the edges and numerous conspicuous stamens. Three-chambered capsules contain many small seeds. The species inhabits sunny grassland, open woods, roadsides, and disturbed ground. It is invasive in New South Wales, Australia, where it competes with pasture plants. It contains hypericin, which can poison livestock by making them extremely sensitive to sunlight. Its extracts are used in herbal products, but can interact dangerously with many medicines. Photographed in Colombia.