Sheyenne National Grasslands, Ransom County, ND.
Federally threatened species, rarea across its range. Photo taken 6/30/06.
A tallgrass prairie species, occupying the edge of prairie wetlands, like the 'bathtub rim'. This species declined, along with hundreds of others, as almost every square yard of the tallgrass prairie was converted to cropland. All that remains are a few weary, threadbare patches in cemeteries, railroad right-of-way, and small, embattled preserves, many tended by volunteers.
Note the Fibonacci sequence, where the rotation of the plant follows the mathematical sequence where numbers are the sum of the previous two numbers on to infinity. This is advanced engineering.