If it has a long tap root such as butterfly weed, globe thistle, and Oriental poppies, don't divide it.
From the boston.com
Echinops, or globe thistle, looks spectacular in sun-dappled light, and adds texture to summer flower arrangements.
From the timesunion.com
They attract bees and butterflies and are at home alongside monarda and globe thistle, while some varieties can be combined well with fuchsias and blue salvias.