The larkspur and the delphinium are close relatives; both are named for the shape of their flowers. The delphinium flower resembles the bottle-like nose of a dolphin; as a result, delphinium comes from the Greek word delphis, meaning "dolphin." The spur, on the other hand, reminded some people of parts of the lark; hence "larkspur," "lark's heel," and "lark's claw." Its more delicate foliage differentiates it from the delphinium.
The delphinium is the birth flower for the month of July, and was used by West Coast Native Americans to make blue dye. European settlers used ground delphinium flowers to make ink. The most ancient use of the delphinium was as a strong external medicine thought to drive away scorpions.
According to Greek legend, Achilles' mother requested that her son's armor be given to the most heroic Greek warrior during the Battle of Troy. To the dismay of the brave warrior Ajax, the armor was awarded to Ulysses. Dejected, Ajax threw himself on his sword, and small blue delphiniums sprung from the blood that fell to the ground. Delphinium petals are marked with the Greek letters AI, the Greek cry of mourning.
Delphiniums signify an open heart and ardent attachment; larkspurs generally symbolize lightness and swiftness.