The narrow-leaved willowherb - Epilobium angustifolium L. and the small-flowered willowherb belong to the evening primrose family. The narrow-leaved willowherb grows up to 2 m tall, the small-flowered one up to 80 cm tall. Flowering time of both species is July to September, the narrow-leaved willowherb has purple flowers, the small-flowered light pink flowers.
Phytotherapeutic use of both species is the dried herb from stems, leaves, flowers and fruits: willowherb - Epilobii herba