• habitat of plant in sand prairie; Big River State Forest north of Oquawka, Henderson County, Illinois
  
• habit of plant in flower; Braidwood Dunes and Savanna Nature Preserve, Will County, Illinois
  
• another plant in flower; sand hill prairie at Hanover Bluff Nature Preserve, JoDaviess County, Illinois — the brown blades of grass are needle grass Stipa spartea
  
• plant with inflorescences and leaves; Foley Sand Prairie Nature Preserve, Lee County, Illinois
  
• inflorescence and flowers; same locality
  
• flowers; Hanover Bluff Nature Preserve, JoDaviess County, Illinois
  
• closeup of flowers
  
• plant with unopened fruits; Foley Sand Prairie Nature Preserve, Lee County, Illinois
  
• unopened fruits; LaBahn Prairie, Bureau County, Illinois
  
• fruits after they have split open
  
• distribution map in Illinois from the Illinois Plant Information Network
  

• habit of plant in flower; Braidwood Dunes and Savanna Nature Preserve, Will County, Illinois
  
• closer view of plant in flower; same locality
  
• flowers with a male regal fritillary (which is listed as Threatened in Illinois); Savanna Army Depot / Lost Mound, Jo Daviess County, Illinois
  
• closeup of flowers ; Rock Island Trail Prairie Nature Preserve, Stark County, Illinois
  
• macro of flowers
  
• extreme closeup of flower showing anthers and the moniliform (bead-like) hairs on the filaments
  
• Click here for a distribution map in Illinois from the Illinois Plant Information Network
  

• habitat plants spreading across the sand prairie; Mason State Tree Nursery, Topeka, Mason County, Illinois
  
• habit showing leaves and fruits; same locality
  
• habit with leaves, a yellow flower, and developing fruits; Big River State Forest north of Oquawka, Henderson County, Illinois
  
• closeup of flower and leaves; same locality
  
• macro of top of fruit showing the sharp spines; I can tell you from personal experence that these will pucture a tire if you drive over one!
  
• Click here for a distribution map in Illinois from the Illinois Plant Information Network
  

• closeup of inflorescence and flowers; cultivated Illinois Natural History Survey, Champaign, Illinois
  
• flower and fruit; same locality
  
• both flower and fruit in longitudinal section; same locality
  
• longitudinal section of flower; same locality
  
• side view of fruit cluster; same locality
  
• top view of fruit cluster; same locality
  
• bottom view of fruit cluster; same locality
  
• fruit in longitudinal section; same locality
  
• Click here for a distribution map in Illinois from the Illinois Plant Information Network
  

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