Donna,
Your description: blooms drooped down in long "strings" with a lacy appearance begs the thought that what you were seeing was not a canna. At least for zone 7b, the chance to have mature blooming cannas in late April or early May (a few weeks back) seems suspect unless the cannas were transplanted from a greenhouse. Without a photo I am afraid you might need to look for another plant?
Kent

Now that's a thought. The foliage looked like cannas, but you're right. I have never seen blooms like that on a canna, and yes, it is very early for them to bloom, even here. Thanks for replying.