i think i know the significance: if u look real carefully it looks like the flower is crying [bella does that a lot in the book] in which i think that it means its a sad story with depression...............but thats wht i think

from stephenie meyer web site:
"Q. What kind of flower is that on the cover, and what does it mean?

A. That is a ruffled tulip. As for the meaning… If you've read the Twilight faq, you know that the apple cover had a lot of meaning for me, and I was an active part of the covering process. However, that experience is more the exception than the rule in the publishing world. Something to keep in mind if you intend to embark on a career as a writer: lots of things you might expect to be under your control are not. Covers, for example. Those are mostly up to the publisher and the marketing and sales departments. So I don't know what the tulip means—I didn't have anything to do with this one."

*Points to daisy_star4444* What she said.

stephenie said herself that there is no significance in it.. i actually seen the picture on a calendar, the publisher or something put it on there.. but there is no real significance to stephenie for sure.

The Apple Cover (Twilight) : Temptation, the forbidden fruit. The Bloody Tulip Cover (New Moon) : It has no real meaning. SM had nothing to do with this one. The Broken Ribbon Cover (Eclipse) : Choosing sides, forced choices, etc..

There have been explanations in almost every other answer comment thing...

You should look at Darkling's explanation I was confused then I read her explanation I understood.(you can't blame me for being confused I am only 11)

I did some research and the flower on the cover is a Parrot Tulip. A Flamming Parrot Tulip to be exact. And I went on Wiki Symbols...and a yellow/white tulip symbolizes a hopeless love and red symbolizes love. SOOO Edward=Red and Jacob=White!

While Bella is talking to Alice, she compares flowers to vampires

yeahh. steph said it had no pointt.

good guesses thoughh!

I agree.

Stephenie Meyers said that it doesnt have a meaning because someone else chose it. But in my opinion the book cover means that Bella is the white flower and she is dying since Edward has gone. The blood represents Edward because of the Vampire thing. But she's been with Edward and the blood leaves a mark on her after he is gone.

it dosnt have a meanin bhind it cause stepanie meyer didnt get 2 choose da picture 4 it!!!!!!!!!!!!!!!

i think the explanations that people gave were good.. but since steph sed it didnt have a meaning then it dsnt.. but i like the ideas people have like sweet twilights.. i would think thats why theres a flower there.. and the one that sweetiecheeks sed..

ive been told tht its Bella's life draining from her thts why its like the red draining from the white.

On her website Stephenie said herself there was no meaning.

Dunno....