Polygonatum biflorum aka Smooth Solomon's Seal

Polygonatum biflorum is a perennial in the asparagus family. Gardeners know it as Solomon's seal or smooth Solomon's seal. Its native range runs from Canada to northeastern Mexico. It grows in woods, thickets, and along roadbanks. Wild plants occur in dry to moist woodland soils. Underground rhizomes support new growth and help plants form colonies. Scars on these rhizomes gave rise to its common name.

Garden plants reach 3–6 feet [0.9–1.8 metres] tall. They spread about 2–4 feet [0.6–1.2 metres] wide. RHS gives a higher height limit of 8.2 feet [2.5 metres]. The stems stand upright or curve into arches. They do not branch and can have a zigzag shape. Smooth green leaves grow in turn along each stem. Each leaf has clear parallel veins and an unbroken edge. Leaves reach 0.5 feet [0.15 metres] long. They turn yellow in fall before dropping.

Small greenish-white flowers hang beneath the leaves in spring. Chicago Botanic Garden lists flowering from March through June. Each leaf axil can hold two to ten flowers. The flowers have six parts and a tubular, bell-like shape. Pollinator insects and ruby-throated hummingbirds visit for nectar. Dark blue to black berries follow the flowers. These showy fruits appear in September and October. Birds visit the fruits, while mammals eat the roots. Deer may eat the leaves.

Grow this plant in moist soil with good drainage. It suits partial shade or deep shade. RHS also lists full sun as an option. Rich soil with plenty of organic matter supports growth. It accepts sand, loam, clay, and chalk across varied pH levels. North Carolina State lists USDA zones 3–9; RHS rates it H7. Use it in woodland, shade, rain, or cottage gardens. It also suits borders and areas where colonies can spread. Divide plants in spring; cut stems down in late autumn. Slugs, snails, and Solomon's seal sawfly can cause damage. Serious disease problems are uncommon.

The berries are unsafe for people to eat. They can cause vomiting and diarrhea. RHS also warns that eating the plant can harm dogs. Some sources record food uses for young shoots and rootstock. North Carolina State specifies boiling both parts before eating. Native Americans used the rhizomes as food. Recorded folk uses include root preparations and poultices. These reports do not establish safe or effective medical use.