C. officinalis

C. officinalis may refer to:
 * Calendula officinalis, a garden plant species
 * Cinchona officinalis, a tree species native to the Amazon Rainforest
 * Cochlearia officinalis, a flowering plant species
 * Corallina officinalis, a calcareous red seaweed species
 * Cyathula officinalis, a plant species native to the China