L. curtisii and L. echinatum are very similar. The first is up to 2cm wide and tends to grow in grassy areas and second grows up to 5cm in woods. This appears to be in a wooded area. L. echinatum also has spines that leave a network of scars when they fall off, which seems to be present here
Matt Welter
2017-09-09
2017-09-09
United States of America, Wisconsin, Navarino Widlife Area, Wisconsin, USA