Probably referring to Setaria.

http://flowerknight.wikia.com/wiki/Green_Foxtail

I think German Iris looks cuter...

http://flowerknight.wikia.com/wiki/German_Iris

I'll pass on the rainbow though, I'm already happy with my Daisy.

http://flowerknight.wikia.com/wiki/Kerria

And the event unit herself is cute, if you somehow missed her.

http://flowerknight.wikia.com/wiki/Hypericum