Polygala senega aka Seneca Snakeroot

Polygala senega is a perennial in the Polygalaceae family. Common names include senega root and rattlesnake snakeroot. It comes from Canada and the northern and eastern United States. Its range spans many Canadian provinces and American states. It is not native to Britain or Ireland. This plant grows in temperate regions. Wild habitats include rocky hills and woods with dry soil. These soils often contain lime.

The plant reaches about 1 foot [0.3 metres] tall. Its spread is also about 1 foot [0.3 metres]. This small size suits beds and sunny woodland edges. It flowers in June. Each flower has both male and female organs. The supplied species accounts give no further flower details. They also lack descriptions of its leaves, stems, or fruit. PFAF reports strong cold tolerance, listing it as hardy to UK zone 2.

Choose soil that holds some moisture but drains well. A moderately fertile soil suits this plant. It can grow in sand, loam, or clay. It accepts mildly acid, neutral, and alkaline conditions. It can also grow in very alkaline soil. Although wild plants occupy dry sites, garden plants prefer retained moisture. Full sun suits it when soil stays moist through growth. Otherwise, light shade may suit it better. Reports differ on its tolerance of shade. One account says it dislikes shade.

Seeds, division, and young shoot cuttings offer ways to propagate it. Sow seed in a cold frame in spring or autumn. Move seedlings into separate pots once large enough to handle. Keep them in a greenhouse through their first winter. Plant them out after the last expected frost. Late spring or early summer suits this step. Take young shoot cuttings in late spring using a frame. PFAF does not flag the species as weedy.

Several Indigenous North American peoples used senega root as medicine. Herbalists have also used it to help clear chest mucus. Its roots contain triterpenoid saponins linked to this effect. These uses do not make it a food plant. PFAF lists no known edible uses. Large amounts can cause severe vomiting and diarrhoea. Reported effects also include dizziness and changes in vision. Avoid medicinal use during pregnancy or breastfeeding. PFAF also warns about salicylate sensitivity and diabetes.