One of the first weeds to herald the arrival of spring on the Colorado Front Range is curly dock (Rumex crispus). In this picture you can see the wavy or curly edges of the leaf, for which the plant is named. The plant is a member of the Polygonaceae family, of which buckwheat and rhubarb are also members.
Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm) on a 49 mm long extension tube.