] For the later Victorians anyway, there were entire books devoted to the "Language of Flowers" and among the many meanings of hyacinths were "constancy" and "unobtrusive loveliness". Both of which Eleanor's friendship, in contrast to IT's, have been teaching Catherine to value properly. I can certainly see Catherine taking the hint when Henry suggests he'd like to teach her more about the meaning of a rose...

This got me thinking, and I tried to Google up some other meanings...

Hyacinth
Growing out of doors, these heavily scented flowers forecast unexpected events; in pots they are a sign of improving circumstances.

And the meaning also seems to be dependant on the colors (what color were they in this scene?)

HYACINTH (GENERAL) - Games and Sports, Rashness, Flower Dedicated to Apollo
HYACINTH (BLUE) - Constancy
HYACINTH (PURPLE) - I am Sorry, Please Forgive Me, Sorrow
HYACINTH (RED OR PINK) - Play
HYACINTH (WHITE) - Loveliness, I'll Pray for You
HYACINTH (YELLOW) - Jealousy