Sanicula canadensis aka Canada Sanicle

Sanicula canadensis is known as Canadian black snakeroot or Canada sanicle. It belongs to the carrot family, Apiaceae. Its native range runs from southeastern Canada through central and eastern parts of the United States. It grows in woods, thickets, and woodland openings. Kew places it in temperate regions. NC State describes it as a herbaceous perennial. Kew instead lists its life cycle as biennial.

Plants reach 0.5–3 feet [0.15–0.91 metres] tall. They spread 0.5–1 foot [0.15–0.30 metres] wide. The form is upright but also spreading. Its green, compound leaves grow alternately along the stems. They have a thin, papery feel and lack hairs. The foliage lasts well through the growing season. The stems have no scent. NC State lists its growth rate as medium.

The small green flowers form umbels and offer little show. Each flower has four or five petals. The large, bur-like inferior ovaries dwarf the flowers. Halictid bees and syrphid flies visit them. Yet the flowers draw relatively few insects. The fruit forms a bur with two seeds. It turns from green to brown as it dries. These burs detach and catch on clothes, hair, and fur. They can be troublesome in a dog's coat.

For garden use, choose partial shade or dappled light. NC State also supports shade and sites with morning sun. The soil should hold moisture but drain well. Humus-rich loam suits the plant, with an acid to neutral pH. It can also cope with soil that dries at times. NC State lists USDA hardiness zones 4–9. PFAF does not confirm its hardiness in Britain. Its growing notes draw on the genus, rather than this species.

Canadian black snakeroot can serve as a native groundcover. NC State suggests borders, mass plantings, and naturalized areas. It resists deer and tolerates deep shade. Seed offers a means of propagation. The plant can also seed itself into unwanted places. This makes its spread worth considering before planting. NC State reports no major pest or disease concerns. Even so, the aphid Aphis saniculae favors it as a host. PFAF records no known food use. It records past root use for heart complaints and menstrual effects, including abortion. Leaves were used as poultices for bruises and swelling. These records do not establish safe or effective treatment. The supplied evidence does not establish this species' toxicity.