This complex structure, less than an inch across, is the flower of Rattlesnake Master, Eryngium yuccifolium. The plant is a traditional treatment for snake bite and is native to the tallgrass prairies of central and eastern North America.
Flower of a Rhododendron, somewhere between pink and purple. The Rhododendron is a flowering shrub in the Heath family. Azaleas are a subgroup.
Sea Holly (Eryngium) is a perennial herb with many uses in food and traditional medicine, and is also grown as an ornamental plant.