Carduus, several sp.
Carex, N. S.
Cassia chamæcrista, marilandica, nictitans, and Tora
Ceanothus americanus
Cephalanthus occidentalis
Cerastium arvense
Cercis canadensis
Chelone glabra and Penstemon
Chenopodium ambrosioides and anthelminticum
Chionanthus virginicus