Dollarweed (Hydrocotyle spp.), often called pennywort, is a perennial weed commonly encountered in lawns, gardens, and other moist areas. It is recognized by its distinctive foliage. Identifying this species relies on observing its unique leaf structure, its low-to-the-ground growth habit, and the specific environments where it thrives. This guide details the markers necessary for clear identification.
The Unique Appearance of Dollarweed Leaves
The most identifiable feature of dollarweed is its foliage, which gives the plant its common name due to its resemblance to a small coin. These leaves are nearly circular and often measure between one and two inches in diameter. The leaf margins are typically slightly scalloped, giving the edges a gently wavy appearance.
The leaves are bright green, shiny, and possess a fleshy texture, often appearing like miniature lily pads. A key identifying detail is its peltate structure: the leaf stalk (petiole) attaches near the center of the leaf blade, rather than at the edge. This central attachment point creates an umbrella-like appearance and distinguishes dollarweed from other common weeds with round leaves.
Stem and Growth Patterns
Dollarweed exhibits a low-growing, creeping habit, allowing it to spread rapidly across the ground surface. It is a warm-season perennial that lives for several years, with above-ground growth dying back in colder months while the root structure remains viable. The plant spreads efficiently through horizontal runners, which can be above-ground stolons or underground rhizomes.
These runners are slender and can root at the nodes. When a node contacts the soil, it establishes a new root system and produces an upright leaf, allowing the plant to quickly form dense mats. The leaf petioles rise directly from these creeping stems, holding the coin-shaped leaves upright, often reaching a height of only a few inches above the soil.
Where Dollarweed Thrives
The presence of dollarweed is a strong indicator of excess moisture in the soil, as it prefers consistently wet conditions. This weed is frequently found in low-lying areas where water tends to collect or in regions with poor soil drainage. It can also appear near leaky irrigation systems or in areas that are frequently overwatered.
Dollarweed is successful in soils that have a high clay content and drain slowly, or in well-drained sandy soils where irrigation is excessive. It is commonly seen in moist, open areas, including roadside ditches and marshes. Its ability to thrive in saturated soil conditions distinguishes its preferred habitat from that of many turfgrasses.