A humble thistle blossom in southern Spain somehow keeps itself up to 18 degrees Fahrenheit cooler than the surrounding air ...

England has a rose, Wales a daffodil, Ireland a shamrock and Scotland the purple, prickly but proud thistle which has been our national emblem for centuries, here’s why.

Thistle, especially Canada thistle, is a persistent weed that you'll need patience to control since you'll have to outlast its extensive root system.