Hydrocotyle umbellata
manyflower marshpennywort
Overview
Hydrocotyle umbellata is a low, mat-forming perennial of wet ground and shallow water, native across the Americas. It spreads by creeping rhizomes and runners to form dense colonies, with round, glossy green peltate leaves 0.5-2 inches (1.5-5 cm) wide held on slender upright stalks 2-6 inches (5-15 cm) tall; the leaf stalk attaches at the center of the blade, like a tiny umbrella. From late spring into fall it produces rounded umbels of many tiny white to greenish flowers on stalks about as tall as the leaves, followed by small ribbed fruits. H. umbellata grows in marshes, pond and ditch margins, wet lawns, seeps, and shallow still water, tolerating both fresh and slightly brackish conditions. It needs constant moisture and fails where the soil dries out. The plant spreads quickly and can overrun small ponds, water-garden margins, and damp turf, so it is often treated as a weed in those settings. Tiny flies and bees visit the flowers, and waterfowl graze the foliage. It tolerates light foot traffic and re-roots readily from fragments, which makes it persistent once established. Plants are evergreen in frost-free areas and die back to the rhizomes after hard freezes.
Native Range
Hydrocotyle umbellata is native to the Americas, widespread in the eastern and southern United States and ranging south through Mexico, the Caribbean, and into South America. It grows in freshwater and brackish marshes, on pond and ditch margins, in wet lawns and seeps, and in shallow still water.Suggested Uses
Grown as a groundcover at pond and stream margins, in bog gardens, rain gardens, and water-garden containers, and between stepping stones in consistently damp ground. It is planted 8-12 inches (20-30 cm) apart, where it knits into a dense mat. The mat holds wet soil and shelters small aquatic animals.How to Identify
Appearance
Size & Dimensions
Height2" - 6"
Width/Spread1' - 3'
Reaches mature size in approximately 1 years
Bloom Information
Detailed Descriptions
Foliage Description
glossy greenGrowing Conditions
Sun Requirements
Requires 4-10 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 umbellata grows in full sun to partial shade with 4-10 hours of light and constantly wet loam, silt, or clay at pH 6.0 to 7.5, including shallow standing water a few inches deep. It needs steady moisture and fails in dry soil. The plant is semi-hardy, staying evergreen in USDA zones 8-11 and dying back to the rhizomes after hard frost. It spreads aggressively by runners and re-roots from fragments, so it is contained in a pond basket or a bordered bed where its spread is not wanted. No fertilizer is needed in fertile wet soil.Pruning
No formal pruning is needed. Runners and excess growth are trimmed or pulled at any time during the season to keep the colony within bounds, and the plant regrows quickly. Removing stray fragments prevents them from re-rooting and spreading.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons