Hypericum perforatum (Perforate St. John's Wort) is an upright perennial with showy, star-shaped, yellow flowers, 1 in. wide (2.5 cm), from early to late summer. Borne in pyramidal clusters, they are produced in great numbers, up to 25–100 per stem. Each flower presents 5 petals, peppered with black dots around the edge and a prominent tuft of yellow-tipped stamens. The stalk-less, oblong or linear, pale green leaves display scattered translucent dots that make the leaf look perforated when held up to the light - hence the common name.