Formely placed in Primulaceae, the genus Lysimachia, according to the lates genetic researches, belongs to the family Myrsinaceae. I have four species of Lysimachia, one of them being native to Croatia - Lysimachia nummularia.
It is native to North America. I have planted it among shrubs in the back side of the border. It is pretty vigorous plant, spreading itself by underground stems. It may be invasive so, do not plant it if you have a lots of space in your border. The leaves are burgundy-purple turning more or less green by mid to late summer and make a lovely contrast to yellow star-like flowers. It will grow in full or partial shade.
Lysimachia punctata 'Alexander'
It has nicely variegated leaves and is very good to brighten up a shady dark corner. The yellow flowers and lanceolate leaves are placed in whorls on the long upright stem. The plant needs moderately moist soil. The leaves edges may turn brown when the soil is dry. My flowers in June.
Lysimachia clethroides (Gooseneck Loosestrife)
The plant has curiously curved inflorescence, hence probably the common name Gooseneck Loosestrife. The flowers appear in July. The plant prefers sunny position but mine is happy in semi-shade. Like other Lysimachias, it grows vigorously spreading itself by the underground stems. It needs lots of space so, pull it regularly out to keep it within the place. Unlike most of Lysimachias that have single yellow flowers, this one bears spikes of white flowers. It makes a superb cut flower.
Lysimachia nummularia has a low growing creeping habit. The stems grow quickly and it is a good ground cover plant. Round leaves are paired along the stem. The flowers are yellow. There are cultivars with "golden" leaves. It needs moist soil with a good portion of organic matter
One of the ways to keep Lysimachia under control and reduce spreading is to plant it in a bottomless pot. Dig in the pot on the place in your flower bed.
I will cut them down to the ground for the winter.