Slippery Slope™ Chinese Roof Iris was found in Sichuan by Darrell Probst (of Coreopsis and Epimedium fame). He introduced it because of its size and vigor, as well as the beauty of its blue purple veined flowers. The centers (signals) of the largest petals are white with dark purple veining. The green leaf blades stay clean and attractive all summer, and Iris tectorum Slippery Slope™ expands to making low growing attractive groundcover. This is an Iris that works well as a green roof plant.