Pennywort
The lawn pennywort (Hydrocotyle sibthorpioides), also called the lawn marshpennywort, is a creeping perennial plant often found as a weed of gardens, pathways and lawns, but occasionally planted for its attractive, glossy foliage.
This plant is a prostrate creeping herb 1 to 2 cm tall with an unlimited spread via the wiry, hollow, green stems that root freely at the nodes.
Leaves are alternate and/or in whorls at the nodes, compound, with 2 stipules, orbicular or nearly so. Palmate veination and lobes, lobes 7, quite variable, generally less than 1 cm wide.
Flowers are borne in simple or compound umbels held on a long peduncle above the foliage mat.
Controlling Pennywort
Control of this plant can be difficult, as it can regrow from very small stolon fragments, and can grow across the crowns of larger plants.
Mowing: Ineffective
Cultivation: Ineffective, as the plant can regrow from very small root fragments
Mulching (for prevention): Effective only as a barrier to seed inoculation. The plant will germinate under mulches.
Pulling: In garden beds, loosen the soil, and try to lift the whole plant, shaking the soil off afterward (the stems are fairly strong). Take care not to leave any stem parts, as the plant can easily regrow from fragments.
Flame: Can kill the plant if burned deeply (the plant is not very drought tolerant)
Barriers: Can be effective, but the edges must be monitored closely
Disposal: Hot compost piles only