Burmannia biflora (northern bluethread)

Centaurium pulchellum (branched centaury)
Centaurium spicatum (spiked centaury)
Centaurium texense (Lady Bird's centaury)
Central African Republic
Centranthus ruber
Centrosema virginianum (spurred butterfly pea)
Cephalanthera damasonium
Cephalanthus occidentalis (common buttonbush)
Cerastium arvense
Cerastium arvense (field chickweed)
Cerastium arvense ssp. velutinum var. velutinum (field chick
Cerastium glomeratum
Cerastium holosteoides
Cerastium nutans var. nutans (nodding chickweed)
Cerastium semidecandrum (fivestamen chickweed)
Ceratostigma plumbaginoides
Cercocarpus montanus (alderleaf mountain mahogany)
Ceropegia linearis
Chad
Chaenomeles x superba
Chaenorhinum minus
Chaenorhinum minus (dwarf snapdragon)
Chaerophyllum bulbosum
Chaerophyllum hirsutum
Chaerophyllum procumbens (spreading chervil)
Chaerophyllum tainturieri (hairyfruit chervil)
Chaetopappa asteroides (Arkansas leastdaisy)
Chamaecrista nictitans (sensitive partridge pea)
Chamaemelum nobile (Roman chamomile)

Image of Burmannia biflora (northern bluethread) 1
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 1: 547.