Hello from Snow Mexico! The Letter C is a huge one, so many general of plants start with C and many, many common names as well. It is a very compelling, Christmas-y, colorful ingredient in Floral Alphabet Soup, and I am looking so forward to your posts of the glorious C's. Here are just three of mine to sweeten the pot. Lets take this one into Christmas...? Unless y'all slow down a lot.
Carex morrowii
Campsis radicans
Clethra alnifolia
Choinodoxa