This is Juncus effusus spiralis, also known as Corkscrew Rush, and Twisted Arrows. This ornamental grass is suitable for water gardens or bogs. It grows to 1 or 2 feet high and likes to live in sun to partial shade. The main attraction of this plant is the corkscrew shaped grass which can be used in cut flower arrangements. USDA Hardiness Zones 4 to 10