Family: Iridaceae Juss.
Distribution: Europe, Caucasus, Southwestern Asia and Northern Africa.
Ecology: It grows on banks of rivers, ponds, lakes, canals, in ditches, mainly at lower altitudes. Flowers from May to June.
Description: A perennial herb with a creeping, branched rhizome and an erect stem up to 150 cm high. The leaves are sword-shaped, the flowers are yellow (rarely white) with violet-brown veins. The fruit is a capsule.
Use: The rhizome is used medicinally.
These images were taken in Czechia, Bohemia, Poděbrady and Prague (dates: 29. 5. 2004 and 4. 8. 2007).