Hydrocotyle bonariensis Comm. ex Lam.

Hydrocotyle bonariensis is a perennial grass, glabrous with many horizontal creeping stems, rooting at each node. It gives off a strong odor when crushed. The leaves are simple, alternate, with circular or largely elliptical lamina, inserted approximately in the middle on a slender vertical petiole. The margin is roughly crenated. The inflorescences are multiple umbels carried by a slender peduncle, usually longer than the leaves. The flowers are white to cream. The fruit is transversely ellipsoid, laterally compressed.
 
First leaves

The first leaves are from underground creeping stems. They are simple and alternate, with circular and peltate lamina, carried by a thin and long petiole. Young leaves are glabrous with crenate margin and have a shiny appearance.
 
General habit

Herbaceous, perennial plant, creeping, rooting at the nodes and developing in dense tuff.
 
Underground system

The root consists of a main taproot and many adventitious taproots developing at each node in contact with the ground.
 
Stem

The slender stem is creeping, partly underground rhizomatous or stoloniferous. It is cylindrical, full, fleshy, glabrous, rooting at the nodes.
 
Leaf

The leaves are simple, alternate carried by a small, fleshy and vertically erect stalk, 2 to 37.5 cm long. The blade is circular to widely elliptical, 1.2 to 12 cm in diameter, and widely peltate, arranged horizontally. The margin is roughly crenate to deeply lobed sometimes. Venation consists of 12 to 20 palmate veins radiating from the insertion point of the petiole. The faces are glabrous.
 
Inflorescence

The inflorescence is a compound umbel atop a slender peduncle and usually longer than the leaves. The main umbel consist of 5-7 rays. At the top of each ray is a whorl of flowers, underpinned by an involucre of ovate to lanceolate bracts, 1 to 2 mm long.
 
Flower

Each flower is carried by a pedicel, 1 to 2 cm long, spread or reflected. The calyx is reduced to small tines sticked to the inferior ovary, the corolla is formed of five oval petals, spread over the ovary, of white to greenish color and of 2 to 2.5 mm in diameter. 5 stamens are fixed alternately with the petals. The ovary with 2 bilocular carpels is located in inferior position. It is topped by 2 short filiform styles of 1 mm long overcome by short stigmas.
 
Fruit

The fruit is a transversely ellipsoid capsule, laterally compressed, 1 to 2 mm long and 2 to 4 mm wide, emarginate at the base and at the top. It consists of 2 mericarps that remain welded together at maturity. The summit is topped by 2 styles, about 1 mm long. The 10 longitudinal ribs are distinct. The seed coat is reddish brown, slightly wrinkled at maturity.