Samolus valerandi aka Brookweed

Samolus valerandi belongs to the primrose family, Primulaceae. Its common names include brookweed and water pimpernel. It is native to Britain and Ireland. Its broad native range spans temperate and subtropical parts of the Old World. It also reaches mountain regions in the tropics. Records place it across Europe and Africa, east to India and China.

This small plant can live as an annual or short-lived perennial. It creeps along the ground and forms basal rosettes. Its stems may stay single or branch. Garden references give a height of about 1 foot (0.3 metres). A wider recorded range runs from 0.16 to 1.64 feet (0.05–0.5 metres). It flowers from June to August, with seeds ripening during July and August. Each flower has both male and female organs. The plant is self-fertile and can pollinate itself.

In the wild, brookweed grows in wet ground and shallow water. Coastal sites form an important part of its habitat. It also grows beside streams, in swamps, and in drying riverbeds. For garden use, give it sun and a steady water supply. It does not suit shade or acid soil. Sandy soil, loam, and clay can all support it. Choose neutral or mildly alkaline soil. It can grow in wet beds or shallow water. Plants can also survive several months under water. It tolerates sea exposure and substantial frost. PFAF lists USDA zones 5–9.

Its small size suits pond edges, bog gardens, and water gardens. Growers can raise new plants from seed or divide them in spring. Sow seed on the surface in a cold frame during spring. Stand the pot in shallow water while seedlings develop. Increase the water depth as the plants grow. Plant strong young plants out in summer. Keep slower seedlings until late spring of the next year. This species also makes use of sites changed by people. The cited 2013 IUCN assessment lists it as Least Concern.

Young leaves can be eaten raw or cooked, though they taste bitter. Sources also record leaf use against scurvy. This records a use, not proof of medical benefit. PFAF and Useful Tropical Plants report no known hazards. The supplied sources give no specific pest or disease problems.