Hydrocotyle umbellata

Hydrocotyle umbellata is an aquatic plant that thrives in wet, sandy habitat. Its English common name is manyflower marshpennywort or dollarweed. It is native to North America and parts of South America. In Brazil it is known as acariçoba and has applications in herbal medicine with purported anxiolytic, analgesic and anti-inflammatory properties. It can also be found growing as an introduced species and sometimes a noxious weed on other continents. It is an edible weed that can be used in salads or as a pot herb.

Description
They are aquatic or underwater herbs, floating or creeping, slightly succulent. The leaves are peltate, orbicular, 0.5–7.5 cm in diameter, crenate or slightly 8–20-lobed; petiole thin, 0.5–40 cm long. Inflorescences in the form of simple umbels with 10–60 flowers or a few peduncles proliferating and embracing whorls of slender-pedicellate flowers, peduncles usually slightly longer than the leaves. Ellipsoid fruit, 1–3 mm in diameter, with obvious and obtuse ribs.