The Titan arum (aka Corpse Flower) isn't really ugly, it just smells bad when it blooms. REALLY bad. Seriously, it's been known to make people faint from the smell.
Rather amusingly, the taxonomic name for the titan arum, Amorphophallus titanum, pretty much means "giant mis-shapen penis." I wonder if Yuuka is commenting on that part...
Also, the fact that she's basically comparing us to flowers known as the "corpse flower" plus the look on her face does NOT bode well for us.
It's the world's ugliest flower, you know.(*)
How 'bout it? Isn't it just like you?
Ah, Rafflesia might do as well.
*No, really.How about a Titan arum?
Oh, no, I was just thinking of what flower would best fit you.