Name: Caltha palustris L.
Croatian name: Kaljužnica
English name: Marsh marigold, Kingcup
This plant loves marshes and wetland and grows in abundance on the stream sides, often in a shallow waters. It is herbaceous perennial plant, with bright yellow flowers and round to kidney like leaves. As is often grows in a large groups it looks quite stunning when in full bloom. That is probably the reason why it is also a popular garden plant with cultivars with double flowers.The flowers usually have five petals and are about 4 cm in diameter. Carpels form into follicles bearing seeds.
carpels forming follicles
Caltha is highly polymorphic species, and it is divided in several subspecies. The plant is poisonous and may cause skin irritations and rushes.