Looking for
μαργαρίτης in the meaning of an egyptian plant
I found
http://www.gutenberg.org/files/31793/31793-h/31793-h.htm
http://www.touregypt.net/featurestories/flowers.htm

This faience tile comes from the excavations of the Egypt Exploration Society in the Great Palace at Amarna.
New Kingdom (1550-1300 BC) / Faience / Great Palace at Amarna
http://www.flickr.com/photos/11413503@N03/2524049521/in/set-72157604145986272















and
μαργαρίτης in the meaning of pearl
I found

Derived from Latin Margarita, which was from Greek μαργαριτης (margarites) meaning "pearl", probably ultimately a borrowing from Sanskrit. Saint Margaret, the patron of expectant mothers, was martyred at Antioch in the 4th century. Later legends told of her escape from a dragon, with which she was often depicted in medieval art.






















http://concordances.org/greek/3135.htm 
http://en.wikipedia.org/wiki/Pearl_oyster
http://en.wikipedia.org/wiki/Pearl