Hydrocotyle vulgaris
marsh pennywort
Western and central Europe and North Africa
Overview
Hydrocotyle vulgaris is a creeping perennial of wet, peaty ground, known for its almost circular leaves. Each bright green leaf is 0.4-1.6 inches (1-4 cm) across and peltate, meaning the long stalk joins at the centre of the blade rather than the edge, with shallow scalloped lobes around the rim. Slender stems creep over the surface and root at the nodes, knitting together into low, open carpets a few inches high. The flowers are tiny and easily missed: clusters of minute greenish-pink blooms sit on short stalks in the leaf axils, often hidden beneath the foliage, from June to August. Small round fruits follow. It grows in bogs, fens, marshes, wet meadows, dune slacks, and pond and ditch margins, on damp, acid to neutral soils that stay wet through the year. Spreading by its rooting runners, it can form extensive patches and may colonise the wet edges of ponds and waterlogged lawns. It dies back in hard winters but holds some leaves through mild ones. Despite the common name pennywort, it is unrelated to the wall pennyworts (Umbilicus spp.).
Native Range
Native to western and central Europe and parts of North Africa, from the British Isles and Scandinavia south to the Mediterranean. It has become naturalized in parts of North America and elsewhere.Suggested Uses
Grown at pond and stream margins, in bog gardens, and in wildlife ponds as a low, spreading cover for wet ground and shallow water. It suits naturalistic and rain-garden plantings. Its vigorous runners make it unsuited to small ponds or tightly planned schemes without root confinement.How to Identify
Appearance
Size & Dimensions
Height1" - 6"
Width/Spread1' - 2'
Reaches mature size in approximately 1 years
Bloom Information
Tiny greenish-pink flowers open from June to August in small clusters on short stalks set in the leaf axils, usually hidden below the leaves. They are pollinated by small insects, after which little rounded, ribbed fruits form. The flowers are far less conspicuous than the round foliage.
Detailed Descriptions
Foliage Description
bright greenGrowing Conditions
Sun Requirements
Requires 4-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Hydrocotyle vulgaris needs permanently moist to wet, acid to neutral soil, pH about 5.0-7.0, in full sun to part shade. It grows at pond and bog margins and in shallow water at the edge, and does not tolerate drying out. It spreads quickly by rooting runners, so it suits bog gardens and pond edges but can overrun small or contained plantings. It is raised easily from rooted pieces of stem pressed into wet soil. It is hardy in most temperate gardens, roughly USDA zones 5-9, dying back in cold winters and reshooting in spring. Confining the roots in a basket or container limits its spread in mixed plantings.Pruning
No pruning is needed. Runners can be pulled back or lifted to keep it within bounds at pond edges. Dead winter foliage can be cleared in spring as new leaves appear.Container Growing
✓ Suitable for container growing