A leaf of the Lungwort Pulmonaria opal.
The scientific name Pulmonaria is derived from Latin pulmo (the lung). In the times of sympathetic magic, the spotted oval leaves of P. officinalis were thought to symbolize diseased, ulcerated lungs, and so were used to treat pulmonary infections. The common name in many languages also refers to lungs, as in English "lungwort" and German "Lungenkraut". In some East European languages, the common name is derived from a word for honey, e.g. Russian "medunitza" and Polish "miodunka".
English colloquial names include Lungwort, Soldiers and Sailors, Spotted dog, Joseph and Mary, Jerusalem Cowslip, Bethlehem Sage.
Description taken from Wikipedia: http://en.wikipedia.org/wiki/Pulmonaria