Oenanthe sarmentosa, commonly known as water parsley, is a perennial herb that is native to riparian zones, wet meadows, and marshes in western North America, ranging from Alaska to California. It typically grows to a height of up to 5 feet and features parsley-like leaves that can reach 12 inches in length on petioles up to 14 inches long. The plant produces an inflorescence consisting of a compound umbel with flowers that have bright white to red-tinged petals, blooming from late spring to mid-summer. The flowers are modest in size but can be quite numerous, creating a delicate, lacy appearance.

Water parsley is valued for its ability to thrive in wet conditions, making it suitable for water gardens, riparian plantings, and wetland restoration projects. It prefers consistently moist to wet soil and can even grow partially submerged in water. While it can be a beautiful addition to appropriate settings, gardeners should be cautious as it has the potential to become invasive outside of its native range. It requires full sun to part shade and benefits from rich, organic soil. There are no significant disease or pest issues, but it can spread aggressively in favorable conditions.CC BY-SA 4.0