Paris quadrifolia aka Herb Paris

Paris quadrifolia, or herb paris, belongs to the Melanthiaceae family. Its native range runs from Europe east to Mongolia. It is native to Britain and Ireland. This woodland perennial grows from rhizomes beneath the soil. In the wild, it grows in damp woods on lime-rich ground. Its leaves fall at the end of the growing season.

The plant forms clumps with stems that stand upright. It reaches about 1.3 feet [0.4 metres] in height. Garden plants can reach 1.6 feet [0.5 metres] tall and wide. Each stem bears one whorl of green, oval leaves. Most whorls have four leaves, though some have three or five. A single flower sits above the leaves in spring. Its narrow green outer petals spread into a star. The inner petals are thin threads with a greenish-white tint. One round, blue-black berry follows the flower.

Give herb paris deep soil with plenty of humus. Keep the ground moist, but allow excess water to drain. The RHS recommends neutral to slightly acidic soil. It lists clay, loam, sand and chalk as suitable soil types. Choose a sheltered site in partial or full shade. Plants For A Future favours dappled shade rather than deep shade. A shaded woodland bed suits its needs. It also fits informal borders, cottage gardens and wildlife gardens. Its unusual flowers and leaf whorls offer interest in shaded beds.

The RHS rates its winter hardiness as H5. Plants For A Future lists USDA zones 5–9. Plants take about two to five years to reach full size. They need no pruning, and disease is rarely a problem. Slugs may damage them. Sow seed in outdoor containers during autumn. Divide established clumps in spring or autumn. Plants For A Future does not flag this species as weedy.

Do not eat this plant; the RHS warns it is harmful. Plants For A Future records no edible uses. It warns that large doses, including fruit, can cause poisoning. Reported effects include nausea, vomiting and dizziness. It also records fatal overdoses in children. Historical medicinal uses do not make it safe for home treatment. The RHS advises gloves and protective gear when handling it. The berries have supplied red dye, while leaves have supplied yellow dye.