Tangled hypericum

Tangled hypericum is an erect perennial herb to 45 cm tall with tangled branches. It reproduces from rhizomes and seed. It could invade open woodlands and agricultural land.

Arrowhead-shaped leaves (5-15 mm long) are arranged opposite each other along much-branched stems. Stems and leaves both have minute black glands, while only the leaves have translucent oil glands.

Short-stalked yellow flowers occur in clusters at branch ends in summer. Each flower has five petals. The fruit (3-4 mm long) is a capsule with three compartments.