Sparganium sp. flower
Pliocene
Rita Blanca Formation
Oldham County, TX USA.
18mm flower on 70mm slab.

Plant.

Sparganium is a genus of aquatic plant known as the bur-reed.  It lives in wetlands of temperate to arctic regions.  Its fossil history extends to the Oligocene of Europe (and questionably to the Late Eocene of the United States at the Florissant site).