Catabrosa aquatica, commonly known as Water Whorl-grass or Brookgrass, is a perennial semi-aquatic grass native to temperate and cool regions of the Northern Hemisphere, as well as southern Chile and Argentina. It thrives in a variety of wet habitats, including wet meadows, stream banks, and lake shores. This grass typically forms dense, bright green tufts and reaches a height of 10-100 cm. Its inflorescence is a loose, open panicle that blooms in the summer, with small, pale green to purplish flowers that are not particularly showy. The plant’s foliage remains attractive throughout the growing season.

Water Whorl-grass is valued for its ability to stabilize soil and prevent erosion in riparian zones. It is often used in wetland restoration projects and can be a component of "rain gardens" designed to manage stormwater runoff. In cultivation, it requires consistently moist to wet soil conditions and can grow in full sun to part shade. While it is not drought-tolerant, it can withstand temporary flooding and is generally low-maintenance. There are no significant disease or pest issues associated with Catabrosa aquatica, but it can become invasive if not managed properly in garden settings.CC BY-SA 4.0