The Nightingale and the Rose
The nightingale and the rose are the traditional symbols of the lover and the beloved in the classical Persian tradition. The nightingale is portrayed as the lover who constantly sings the praises of his beloved and is unable to part from her. The rose is a symbol of beauty whose pride and vanity often inflicts pain on her lover just as the rose can inflict harm with its thorns.
Hafez, the great Iranian poet, often uses this symbolism in a most touching and beautiful manner. Here's an example:

The rose has flushed red, the bud has burst, And drunk with joy is the nightingale Hail, Sufis! lovers of wine, all hail! For wine is proclaimed to a world athirst. Like a rock your repentance seemed to you; Behold the marvel! of what avail Was your rock, for a goblet has cleft it in two!

Lotus
The first known artistic representation of the lotus flower appears on the walls of Persepolis 2500 years ago. It was an abstract flower shape with 12 petals. Its symbolism is shrouded in mystery but we know that the number 12 was considered sacred in the ancient Persian society.

Persepolis Lotus	Mamqan Lotus

Since then the lotus flower has been used by Persian artists in a wide variety of artistic representation. It has been used as an ornament for book covers, in lacquer work as well as on rugs, tiles, fabrics and wood.