Willow Herb and White Willow

Hello, I'm Michael from Malaysia, I would like to know the difference between willow herb (Epilobium parviflorum) that I have bought from your company and the white willow (Salix alba / Salicaceae).

The white willow tree is the source of an astringent bark that is used for its analgesic (pain-relieving) and febrifuge (temperature lowering) properties. The willow tree is a hardy native of the northern temperate forests.
Willowherb is entirely different. It is a herbaceous perennial, not a tree, and has very different medicinal effects. It is well known for its beneficial effects on the prostate gland, helping to reduce swelling, and is used for disorders of the urinary system.
Despite the similarity of the names, the two herbs cannot be used interchangebly and must not be confused with each other.