Species | Subspecies/ variety | Common Name | Status | Known/Suspect | Field Office |
| Calamagrostis foliosa | | Leafy Reed Grass | California State Rare and California Native Plant Society List 4. | K | Arcata |
| Calicium viride | | Frog Stubble | BLM Sensitive | S | Arcata, Redding |
| Calochortus clavatus | var. avius | Pleasant Valley Mariposa Lily | BLM Sensitive, California Native Plant Society List 1B | S | Folsom |
| Calochortus dunnii | | Dunn's Mariposa Lily | California State Rare, California Native Plant Society List 1B | K | Palm Springs |
| Calochortus excavatus | | Inyo County Star-Tulip | BLM Sensitive, California Native Plant Society List 1B | K | Bishop |
| Calochortus greenei | | Greene's Mariposa Lily | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Calochortus longebarbatus | var. longebarbatus | Long-Haired Star-Tulip | BLM Sensitive, California Native Plant Society List 1B.2 | S | Alturas, Redding |
| Calochortus monanthus | | Shasta River Mariposa | BLM Sensitive, California Native Plant Society List 1A | S | Redding |
| Calochortus obispoensis | | San Luis Mariposa Lily | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Calochortus persistens | | Siskiyou Mariposa Lily | Federal Candidate, California State Rare, California Native Plant Society List 1B | S | Redding |
| Calochortus simulans | | San Luis Obispo Mariposa Lily | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Calochortus striatus | | Alkali Mariposa Lily | BLM Sensitive, California Native Plant Society List 1B | K | Barstow, Ridgecrest, Bakersfield |
| Calochortus westonii | | Shirley Meadows Star-Tulip | BLM Sensitive, California Native Plant Society List 1B | K | Bakersfield |
| Calycadenia hooveri | | Hoover's Calycadenia | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Calycadenia oppositifolia | | Butte County Calycadenia | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Calycadenia villosa | | Dwarf Calycadenia | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Calyptridium pulchellum | | Mariposa Pussypaws | Federal Threatened, California Native Plant Society List 1B | S | Bakersfield |
| Calystegia atriplicifolia | ssp. buttenesis | Butte County Morning-Glory | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Calystegia collina | ssp. tridactylosa | Serpentine Morning Glory | | | |
| Calystegia collina | ssp. venusta | South Coast Range Morning-Glory | BLM Sensitive, California Native Plant Society List 4 | K | Hollister |
| Calystegia stebbinsii | | Stebbins' Morning Glory | Federal Endangered, California State Endangered, California Native Plant Society List 1B | K | Mother Lode |
| Camissonia benitensis | | San Benito Evening-Primrose | Federal Threatened, California Native Plant Society List 1B | K | Hollister |
| Camissonia hardhamiae | | Hardham's Evening-Primrose | BLM Sensitive, California Native Plant Society List 1B | S | Hollister |
| Camissonia integrifolia | | Kern River Evening-Primrose | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Campanula sharsmithiae | | Sharsmith's Harebell | BLM Sensitive, California Native Plant Society List 1B | S | Hollister |
| Campanula shetleri | | Castle Crag's Harebell | BLM Sensitive, California Native Plant Society List 1B | S | Redding |
| Canbya candida | | Pygmy Poppy | BLM Sensitive, California Native Plant Society List 1B | K | Bakersfield |
| Carex livida | | Livid Sedge | BLM Sensitive, California Native Plant Society List 1A | S | Redding |
| Carex obispoensis | | San Luis Obispo Sedge | BLM Sensitive, California Native Plant Society List 1B | K | Bakersfield |
| Carlquistia muirii | | Muir's Raillardella | BLM Sensitive, California Native Plant Society List 1B | K | Ridgecrest, Bakersfield |
| Carpenteria californica | | Tree-Anemone | California State Threatened, California Native Plant Society List 1B | S | Bakersfield |
| Castilleja ambigua | ssp. humboldtiensis | Humbodlt Bay Owl's-Clover | BLM Sensitive, California Native Plant Society List 1B | K | Arcata |
| Castilleja campestris | ssp. succulenta | Succulent Owl's Clover | Federal Threatened, California State Endangered, California Native Plant Society List 1B | K | Bakersfield, Hollister |
| Castilleja densiflora | ssp. obispoensis | Obispo Indian Paintbrush | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Castilleja gleasonii | | Mount Gleason Indian Paintbrush | California State Rare, California Native Plant Society List 1B | S | Palm Springs |
| Castilleja mendocinensis | | Mendocino Coast Paintbrush | BLM Sensitive, California Native Plant Society List 1B | S | Arcata |
| Castilleja rubicundula | ssp. rubicundula | Pink Creamsacs | BLM Sensitive, California Native Plant Society List 1B | S | Redding |
| Caulanthus californicus | | California Jewelflower | Federal Endangered, California State Endangered, California Native Plant Society List 1B | K | Hollister, Bakersfield |
| Caulanthus coulteri | var. lemmonii | Lemmon's Jewelflower | BLM Sensitive, California Native Plant Society List 1B | K | Bakersfield |
| Caulostramina jaegeri | | Jaeger's Caulostramina | BLM Sensitive, California Native Plant Society List 1B | K | Bishop, Ridgecrest |
| Ceanothus confusus | | Rincon Ridge Ceanothus | BLM Sensitive, California Native Plant Society List 1B | S | Ukiah |
| Ceanothus cyaneus | | Lakeside Ceanothus | BLM Sensitive, California Native Plant Society List 1B | K | Palm Springs |
| Ceanothus divergens | | Calistoga Ceanothus | BLM Sensitive, California Native Plant Society List 1B | S | Ukiah |
| Ceanothus ferrisae | | Coyote Ceanothus | Federal Endangered, California Native Plant Society List 1B | S | Hollister |
| Ceanothus hearstiorum | | Hearst's Ceanothus | California State Rare, California Native Plant Society List 1B | S | Hollister |
| Ceanothus roderickii | | Pine Hill Ceanothus | Federal Endangered, California State Rare, California Native Plant Society List 1B | K | Mother Lode |
| Centromadia parryi | ssp. congdonii | Congdon's Tarplant | BLM Sensitive, California Native Plant Society List 1B | K | Hollister |
| Chaenactis suffrutescens | | Shasta Chaenactis | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Chamaesyce hooveri | | Hoover's Spurge | Federal Threatened, California Native Plant Society List 1B | S | Redding |
| Chamaesyce ocellata | ssp. rattanii | Stony Creek Spurge | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Chamaesyce platysperma | | Flat-Seeded Spurge | BLM Sensitive, California Native Plant Society List 1B | S | Palm Springs, El Centro |
| Chlorogalum grandiflorum | | Red Hills Soaproot | BLM Sensitive, California Native Plant Society List 1B | K | Mother Lode |
| Chlorogalum pomeridianum | var. minus | Dwarf Soaproot | BLM Sensitive, California Native Plant Society List 1B | K | Ukiah, Redding |
| Chlorogalum purpureum | var. purpureum | Purple Amole | Federal Threatened, California Native Plant Society List 1B | S | Hollister, Bakersfield |
| Choiromyces venosus | | Hypogeous Truffle | BLM Sensitive | K | Arcata |
| Chorizanthe biloba | var. immemora | San Benito Spineflower | BLM Sensitive, California Native Plant Society List 1B | K | Hollister |
| Chorizanthe breweri | | Brewer's Spineflower | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Chorizanthe orcuttiana | | Orcutt Spineflower | Federal Endangered, California State Endangered, California Native Plant Society List 1B | S | Palm Springs |
| Chorizanthe pungens | var. pungens | Monterey Spineflower | Federal Threatened, California Native Plant Society List 1B | K | Hollister |
| Chorizanthe rectispina | | Straight-Awned Spineflower | BLM Sensitive, California Native Plant Society List 1B | K | Bakersfield, Hollister |
| Cirsium ciliolatum | | Ashland Thistle | California State Endangered, California Native Plant Society List 2 | S | Redding |
| Cirsium crassicaule | | Slough Thistle | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Cirsium fontinale | var. obispoense | Chorro Creek Bog Thistle | Federal Endangered, California State Endangered, California Native Plant Society List 1B | S | Bakersfield |
| Cirsium fontinale | var. campylon | Chorro Creek Bog Thistle | BLM Sensitive, California Native Plant Society List 1B | S | Hollister |
| Cirsium loncholepis | | La Graciosa Thistle | Federal Endangered, California State Threatened, California Native Plant Society List 1B | S | Bakersfield |
| Cirsium rhothophilum | | Surf Thistle | California State Threatened, California Native Plant Society List 1B | K | Bakersfield |
| Clarkia australis | | Small Southern Clarkia | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Clarkia biloba | ssp. australis | Mariposa Clarkia | BLM Sensitive, California Native Plant Society List 1B | K | Mother Lode |
| Clarkia biloba | ssp. brandegeae | Brandegee's Clarkia | BLM Sensitive, California Native Plant Society List 1B | K | Mother Lode, Redding |
| Clarkia borealis | ssp. arida | Shasta Clarkia | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Clarkia borealis | ssp. borealis | Northern Clarkia | BLM Sensitive, California Native Plant Society List 1B | S | Redding |
| Clarkia breweri | | Brewer's Clarkia | BLM Sensitive, California Native Plant Society List 4 | K | Hollister |
| Clarkia gracilis | ssp. albicaulis | White-Stemmed Clarkia | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Clarkia mildrediae | ssp. mildrediae | Mildred's Clarkia | BLM Sensitive, California Native Plant Society List 1B | S | Redding |
| Clarkia mosquinii | | Mosquin's Clarkia | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Clarkia rostrata | | Beaked Clarkia | BLM Sensitive, California Native Plant Society List 1B | K | Mother Lode |
| Clarkia springvillensis | | Springville Clarkia | Federal Threatened, California State Endangered, California Native Plant Society List 1B | S | Bakersfield |
| Clarkia tembloriensis | ssp. calientensis | Caliente Clarkia | BLM Sensitive, California Native Plant Society List 1B | S | Bakersfield |
| Clavariadelphus ligula | | Strap Coral | BLM Sensitive | S | Arcata |
| Clavulina castanopes | var. lignicola | Hairy-Stemmed Coral | BLM Sensitive | S | Arcata |
| Clitocybe subditopoda | | Little Brown Mushroom | BLM Sensitive | K | Arcata |
| Collybia racemosa | | Branched Collybia | BLM Sensitive | K | Arcata |
| Cordyceps ophioglossoides | | Truffle Eater | BLM Sensitive | S | Arcata |
| Cordylanthus maritimus | ssp. palustris | Point Reyes Birds-Beak | BLM Sensitive, California Native Plant Society List 1B | K | Arcata |
| Cordylanthus mollis | ssp. hispidus | Hispid Bird's Beak | BLM Sensitive, California Native Plant Society List 1B | S | Hollister, Bakersfield |
| Cordylanthus nidularius | | Mount Diablo Bird's-Beak | California State Rare, California Native Plant Society List 1B | S | Hollister |
| Cordylanthus rigidus | ssp. littoralis | Seaside Bird's-Beak | California State Endangered, California Native Plant Society List 1B | K | Hollister, Bakersfield |
| Cordylanthus tecopensis | | Tecopa Bird's Beak | BLM Sensitive, California Native Plant Society List 1B | K | Barstow |
| Cordylanthus tenuis | ssp. pallescens | Pallid Bird's Beak | BLM Sensitive, California Native Plant Society List 1B | S | Redding |
| Coreopsis hamiltonii | | Mount Hamilton Coreopsis | BLM Sensitive, California Native Plant Society List 1B | K | Hollister |
| Croton wigginsii | | Wiggins' Croton | California State Rare, California Native Plant Society List 2 | K | El Centro |
| Cryptantha crinita | | Silky Cryptantha | BLM Sensitive, California Native Plant Society List 1B | K | Redding |
| Cryptantha ganderi | | Gander's Cryptantha | BLM Sensitive, California Native Plant Society List 1B | S | Palm Springs |
| Cryptantha mariposae | | Mariposa Cryptantha | BLM Sensitive, California Native Plant Society List 1B | K | Mother Lode |
| Cryptantha roosiorum | | Bristlecone Cryptantha | California State Rare, California Native Plant Society List 1B | K | Ridgecrest, Bishop |
| Cryptantha schoolcraftii | | Schoolcraft's Cryptantha | BLM Sensitive, California Native Plant Society NV Watch | K | Surprise |
| Cupressus arizonica | ssp. nevadensis | Piute Cypress | BLM Sensitive, California Native Plant Society List 1B | K | Bakersfield |
| Cupressus forbesii | | Tecate Cypress | BLM Sensitive, California Native Plant Society List 1B | K | Palm Springs |
| Cusickiella quadricostata | | Bodie Hills Cusickiella | BLM Sensitive, California Native Plant Society List 1B | K | Bishop |
| Cymopterus deserticola | | Desert Cymopterus | BLM Sensitive, California Native Plant Society List 1B | K | Barstow, Ridgecrest |
| Cymopterus ripleyi | var. saniculoides | Ripley's Cymopterus | BLM Sensitive, California Native Plant Society List 1B | K | Ridgecrest |
| Cypripedium fasciculatum | | Clustered Lady's Slipper | BLM Sensitive, California Native Plants Society List 4 | K | Redding |
| Cypripedium montanum | | Mountain Lady's Slipper | BLM Sensitive, California Native Plants Society List 4 | K | Redding |
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