They shall spring up as among the grass. The LXX. have, "As grass among the waters;" and this reading is followed by Bishop Lowth, Ewald, and Mr. Cheyne. But there does not seem to be any necessity for departing from the existing Hebrew text.
As willows. There is some doubt whether the Hebrew word used ('ereb) is rightly translated "willows." The modern yarab seems certainly not to be a "willow," but rather a species of Viburnum. It is, however, most strictly a water-plant, growing only "near flowing water."