Okay, I changed my tune after doing a little digging.
No reviews anywhere (whois has them going back to 2009, you would expect someone to have written a review somewhere by now), and it looks like even if they are legit company they must be just shipping their flowers internationally, which you can get a reputable and bigger floral company to do.
That site seems to have a few others in its network, all without external reviews:
flowerwide.com
flowersia.com
floristclub.com
Used reverse image, other sites using same flower images. Looks like same person set up all the sites.
shanghai-flowers.com
philippineroses.com
hongkongflowerstore.com
hongkongroses.com
chinafloristshop.com
yunnanflowers.com
flowers.com.hk
mexicoflorista.com
... you get the idea.
If they initially asked you do do business through PayPal, and their site says they don't ask for the CC number, then do NOT give them your credit card. When I first read your post I thought you gave them the number already, but there is zero reason to give them your card number if they supposedly go through PayPal.
I'm also not seeing a PayPal verified seal, so I wouldn't trust paying through that way, either.
Contacts seem to be through SMS via VoIP only (Skype), generic Gmail accounts, and no physical addresses. Big red flag.