Ulva clathratioides (G. Kraft, G. T. Kraft, and R. F. Waller 2010) is a green alga belonging to the section Enteromorpha of the genus Ulva. This Ulva grows in tubular forms rather than blades or sheets. Ulva clathratioides resembles U. clahrata, which grows as branched tubes but U. clathrioides is thinner and more finely branched. It was described genetically from Australia and requires molecular methods for detection. It has been found in Japan, Hawaii, and the East and West Coasts of North America. In 2012 it was found in Elkhorn Slough, California. On the East Coast it was found in Narragansett Bay, Rhode Island, in 2008, and in Jamaica Bay, New York in 2015. This alga is small (60–50 mm) and easily overlooked.