B, bamboo shoots, bayberry, hawthorn belong to plants, not "delicacies" food, B is wrong;
C. Mushrooms, Hericium erinaceus and Auricularia auricula belong to fungi and mushrooms, and belong to "delicacies" food. C is correct;
D. Artemisia selengensis, bracken and Nostoc flagelliforme belong to plants, not to "delicacies", and D is wrong;
So choose: C.