Small Bur-reed - Sparganium natans
This bur-reed, with narrow leaves that float on the surface of the water, can be found in shallow ponds and lakes above about 5000 feet. Photographed (left) at Tipsoo Lake on September 3, 2010, (center) at a pond in the Reflection Lakes group on August 1, 2014 and again (right) on September 9, 2016.