Both Uses

perennial
in
A Gentleman in Moscow
(Edited)

I have heard some very distressing things about you, my boy....For Princess Poliakova, a perennial victim of her own heart, it had been Oh, as in Oh, Alexander.
p. 49.1 *

perennial = recurring again and again
Through a narrow door at the back of her shop was that niche with a light green counter where stems had been snipped and roses dethorned, where even now one could find scattered across the floor the dried petals of ten perennials essential to the making of potions.
p. 56.8 *

perennials = flowers or plans that lives more than 2 years

Definitions:

(1) (perennial as in: a perennial stream)
lasting a long time, or forever
(2) (perennial as in: perennial candidate every 4 years)
recurring again and again
(3) (perennial as in: perennial flower)
a flower or other plant that lives more than two years

Perennials are contrasted to annuals (which must be replaced each year and typically only flower for a single season).
(4) (meaning too rare to warrant focus)