Coast Redwood
Colorado Blue Spruce
Colorado Four O' Clock
Colorado Spruce
Columbine
Columnar Norway Maple
Common Butterfly Bush
Common Edible Fig
Common Field or Slender Sedge
Common Fig
Common Garden Petunia
Common Hackberry
Common Lilac
Common Morning Glory
Common Snowberry
Common Thrift
Common Yarrow
Common Yarrow, Milfoil, Sneezewort