Some Flowers Close At Night

This is something curious I found about The Hunger Games: 

Primrose bush

The character of Prim's full name is Primrose which is also the name of a bush with small flowers. Rue comes from the name of a small mountain flower. Both of them, are small and have a nice smell. Also, they both have blossoms that close at night. This symbolically recalls the fact that Rue died just before the night fell.

The flower from which Rue's name comes