Although this prickly flowered cactus is sometimes referred to as the king cup cactus, it is fairly small standing less than a foot tall. This cactus is also known as the claret cup hedgehog because of its spiny resemblance to a hedgehog and cup-shaped flowers. Its spines help deter herbivores and the flowers retain moisture for the plant. I came across this cactus while hiking a rocky trail in Colorado Bend State Park. As you can see from the picture, this cactus typically grows in gravelly soil. I was drawn to its reddish flowers, which happen to remain open night and day, unlike many cacti flowers that close at night. The flowers bloom for about 3 to 5 days from April to June and are pollinated by hummingbirds.