We all know at this point that Astarion's name means "little star".
But Larian decided that they wanted to go all in with the details and they delivered!
The flower you can place on his tomb in the final romance scene (which I think is such a cute and tender gesture and I love his reaction to it), seems to be an Ornithogalum umbellatum, a star-shaped white flower with six petals. Among the plant's many common names, there are summer snowflake, starflower, and star-of-Bethlehem.
Moreover, in the language of flowers, its meanings are related to trauma, mourning, and welcoming pain without repressing it.
According to Doctor Edward Bach (1886 – 1936), these flowers are "For those who find themselves in a state of great anguish due to situations that, in a given period, have caused so much unhappiness", and can be used to help with the aftermath of a trauma, the alleviation of pain and the mourning process.
