What gift should the groom send the bride on the morning of the wedding?

That depends on the bride.

If you, (I assume you are the groom), really know and love her, you will know her personality, correct?

If you need an idea, a giant bouquet of her favorite flowers might be a good idea, complete with a handwritten letter filled with your own loving Words.

Or, maybe a piece of jewelry, like a necklace (not a ring!), that would match her wedding dress to wear at the ceremony.