Hypericum is a genus of herbs (ours), annual or perennial.
Leaves opposite, entire, usually sprinkled with tiny glandular dots.
Flowers yellow, 4-5 parted, radially symmetrical, petals with edges overlapping (convolute), sepals persistent, often unequal, stamens 5-numerous, ovary superior, 2-5 parted, with as many styles; inflorescence usually branched with topmost flowers blooming first (cymose).
Fruit often red at first, becoming dry, cone-shaped capsules, style(s) persistent at tip, splitting open to release numerous seeds.

Hypericum patulum flower.commons.wikimedia.org (Accessed 1/2016).