Unique sculpture showcasing two species of water caltrop, also knows as Devil Pods (Trapa Bicornis and Trapa Natans).

These species are floating annual aquatic plants growing in slow moving fresh water up to 5 m deep.
The Caltrop was eaten in China and India and other parts of Europe for thousands of years, but was only introduced to the US in 1874 as a planting in the Harvard University Botanic Garden. Staff Gardner Louis Guerineau took it upon himself to throw seeds in to fresh ponds and other Cambridge waterways.
At this time caltrops are found all over the US and is declared as an invasive species in a lot of states.