Ibn Sina, also known as Bu Ali Sina, Abu Ali Sina or Avicenna was an 11th century Persian polymath. Apart from philosophy, one area that he wrote extensively on is medicine, and among his most famous books is the Canon of Medicine.
I visited his tomb a few years ago in Hamedan, in western Iran. The walls of the interior were decorated with encased medicinal plants and their uses mentioned by him in various texts.
His mausoleum could also be seen on the old 200 rial bill (below) from the time of the Shah.