c175 made one thing clear: seems that Hiroshi likes connecting Brides of Nurarihyon with flowers...
Youhime - she was born when Sakura was in bloom and Nurarihyon likes to compare her with Sakura
Yamabuki Otome - in translation Kerria Maiden... 'nuff said
Nura Wakana - c175 showed that she holds this flower dear
Oikawa Tsurara - the arctic flower Saxifraga was mentioned when she and Rikuo Matoied
Kitsune - offer her your heart and she will gladly accept it ^_^
Other girls have no mentioned flower connections AFAIK