Argentina anserina aka Silverweed Cinquefoil

Argentina anserina, or silverweed, belongs to the rose family. It is a perennial, so it lives for many years. Sources also name it Potentilla anserina. Its native range spans the mild parts of the Northern Hemisphere into northern Mexico. It is native to Britain and Ireland. Wild plants grow in ditches and damp, lime-rich soil. They also grow as weeds in soil tilled for crops.

This low plant forms mats as its creeping runners spread. White hairs coat these stems, which root at their nodes. Each rooted node can form a new plant. Garden plants reach about 1 foot [0.3 metres] tall. Reported heights range from 0.4 to 1.6 feet [0.12–0.5 metres]. Spread can reach 3 feet [0.91 metres]. RHS gives smaller widths. Leaves grow in tufts near the ground and fall in winter. Each pinnate leaf has many small, toothed leaflets in paired rows. Thick hairs give the leaves their silver look. Leaves can reach 0.7 feet [0.2 metres] long.

Bright yellow flowers rise one per bare stalk above the runners. Each flower has five petals around many short yellow stamens. Flowers reach about an inch across. Missouri Botanical Garden lists blooms from June to August. RHS also notes blooms in late spring. The flowers and silver leaves suit gardens with an informal style. They also suit wildflower meadows. Its low mats cover ground beside ponds and streams. Plants cope with some foot traffic.

Grow silverweed in full sun and moist soil. It tolerates light shade, but not full shade. RHS lists chalk, clay, loam, and sand as suitable soils. It prefers neutral to alkaline soil but copes with poor drainage. Once plants take root, they cope with some drought. They still prefer moist soil. Cool summers suit it best. Hot, humid summers south of USDA zone 7 can cause poor growth. Sources list USDA zones 4–7 and UK hardiness H7. Plants need no pruning and can spread through runners or seed. Divide plants or sow seed to raise more. Few pests cause trouble, though honey fungus may occur.

People eat the roots raw or cooked, or dry them into flour. They also eat young shoots raw and use leaves for tea. PFAF lists past use as medicine for diarrhoea and sore throats. These records do not prove that such treatments work. PFAF also notes that it may irritate the stomach. RHS warns not to eat the fruit. It also advises wearing gloves for protection when handling the plant. Its fruit warning also applies to pets.