Caesalpinia
    gilliesii (Yellow bird-of-paradise)*
    virgata, see Hoffmanseggia microphylla
Cakile maritima (Sea rocket)*
Calamagrostis purpurascens (Purple reedgrass)
Calandrinia
    ambigua, see Cistanthe ambigua
    breweri (Brewer's red maids)
    ciliata, see Calandrinia menziesii
    maritima, see Cistanthe maritima
    menziesii (Red maids)
California macrophylla (White-flowered filaree)
Calliandra
    eriophylla (Pink fairy duster)
Callitriche
    heterophylla var. bolanderi (Water-starwort)
    palustris (Vernal water-starwort)
Calocedrus decurrens (Incense-cedar)
Calochortus
    albus (Fairy lantern)
    catalinae (Catalina mariposa lily)
    clavatus var. pallidus (Yellow mariposa lily)
    clavatus var. gracilis (Slender mariposa lily)
    concolor (Golden bowl mariposa lily)
    dunnii (Dunn's mariposa lily)
    fimbriatus (Late-flowering mariposa lily)
    flexuosus (Winding mariposa lily)
    invenustus (Plain mariposa lily)
    kennedyi var. kennedyi (Red mariposa lily)
    kennedyi var. munzii (Desert mariposa lily)
    palmeri var. munzii (Munz's mariposa lily)
    palmeri var. palmeri (Palmer's mariposa lily)
    plummerae (Plummer's mariposa lily)
    splendens (Splendid mariposa lily)
    striatus (Alkali mariposa lily)
    venustus (Butterfly mariposa lily)
    weedii var. intermedius (Intermediate mariposa lily)
    weedii var. vestus, see Calochortus fimbriatus
    weedii var. weedii (Weed's mariposa lily)
Calycanthus occidentalis (Spicebush)*
Calycoseris
    parryi (Yellow tackstem)
    wrightii (White tackstem)
Calyptridium
    monandrum (Sand cress)
    monospermum (One-seeded pussypaws)
    parryi var. parryi (Parry's pussypaws)
    pygmaeum (Pygmy pussypaws)
Calystegia
    collina ssp. venusta (Coast range bindweed)
    macrostegia ssp. amplissima (Southern island morning glory)
    macrostegia ssp. arida (Southern California morning glory)
    macrostegia ssp. cyclostegia (Coast morning glory)
    macrostegia ssp. macrostegia (Northern island morning glory)
    malacophylla ssp. pedicellata (Jepson's morning glory)
    occidentalis ssp. fulcrata (Western morning glory)
    peirsonii (Peirson's morning glory)
    soldanella (Beach morning glory)
Camissonia
    bistorta, see Camissoniopsis bistorta
    boothii ssp. condensata, see Eremothera boothii ssp. condensata
    boothii ssp. decorticans, see Eremothera boothii ssp. decorticans
    boothii ssp. desertorum, see Eremothera boothii ssp. desertorum
    boothii ssp. intermedia, see Eremothera boothii ssp. intermedia
    brevipes ssp. brevipes, see Chylismia brevipes ssp. brevipes
    californica, see Eulobus californicus
    campestris ssp. campestris (Mojave sun cup)
    cardiophylla ssp. cardiophylla, see Chylismia cardiophylla ssp. cardiophylla
    cheiranthifolia ssp. cheiranthifolia, see Camissoniopsis cheiranthifolia ssp. cheiranthifolia
    cheiranthifolia ssp. suffruticosa, see Camissoniopsis cheiranthifolia ssp. suffruticosa
    claviformis ssp. aurantiaca, see Chylismia claviformis ssp. aurantiaca
    claviformis ssp. claviformis, see Chylismia claviformis ssp. claviformis
    claviformis ssp. funerea, see Chylismia claviformis ssp. funerea
    claviformis ssp. lancifolia, see Chylismia claviformis ssp. lancifolia
    claviformis ssp. peirsonii, see Chylismia claviformis ssp. peirsonii
    confusa, see Camissoniopsis confusa
    hirtella, see Camissoniopsis hirtella
    intermedia, see Camissoniopsis intermedia
    kernensis ssp. gilmanii (Kern sun cup)
    lewisii (Lewis's sun cup)
    micrantha, see Camissoniopsis micrantha
    pallida ssp. pallida, see Camissoniopsis pallida ssp. pallida
    palmeri, see Tetrapteron palmeri
    pterosperma, see Chylismiella pterosperma
    pusilla (Little wiry sun cup)
    refracta, see Eremothera refracta
    robusta, see Camissoniopsis robusta
    strigulosa (Strigose sun cup)
    walkeri ssp. tortilis, see Chylisma walkeri ssp. tortilis
Camissoniopsis
    bistorta (Common sun cup)
    cheiranthifolia ssp. cheiranthifolia (Channel Islands beach primrose)
    cheiranthifolia ssp. suffruticosa (Beach primrose)
    confusa (San Bernardino sun cup)
    hirtella (Hairy sun cup)
    ignota (Jurupa Hills sun cup)
    intermedia (Intermediate sun cup)
    micrantha (Small evening primrose)
    pallida ssp. pallida (Pale primrose)
    robusta (Robust sun cup)
Canbya candida (Pygmy poppy)
Capsella bursa-pastoris (Shepherd's purse)*
Cardamine
    californica (Milkmaids)
    oligosperma (Bitter cress)
Cardionema ramosissimum (Sandmat)
Carduus pycnocephalus ssp. pycnocephalus (Italian thistle)*
Carex
    alma (Sturdy sedge)
    aurea (Golden sedge)
    bolanderi (Bolander's sedge)
    densa (Dense sedge)
    filifolia var. erostrata (Sagebrush sedge)
    fracta (Fragile-sheathed sedge)
    heteroneura (Smooth-fruited sedge)
    multicaulis (Forest sedge)
    pellita (Woolly sedge)
    praegracilis (Clustered field sedge)
    rossii (Ross's sedge)
    senta (Western rough sedge)
    spissa (San Diego sedge)
    subfusca (Rusty slender sedge)
    triquetra (Triangular-fruit sedge)
Carlowrightia arizonica (Arizona carlowrightia)
Carnegiea gigantea (Giant saguaro)
Carpenteria californica (Bush anemone)*
Carpobrotus
    chilensis (Sea fig)*
    edulis (Hottentot fig)*
Carthamus tinctorius (Safflower)*
Castela emoryi (Crucifixion thorn)
Castilleja
    affinis ssp. affinis (Coast paintbrush)
    angustifolia, see Castilleja chromosa
    applegatei ssp. martinii (Martin's paintbrush)
    chromosa (Desert paintbrush)
    cinerea (Ashy-gray paintbrush)
    densiflora ssp. gracilis (Dense-flowered owl's clover)
    exserta ssp. exserta (Purple owl's clover)
    exserta ssp. venusta (Mojave owl's clover)
    foliolosa (Woolly paintbrush)
    gleasoni (Mount Gleason paintbrush)
    hololeuca (Island paintbrush)
    lanata ssp. hololeuca, see Castilleja hololeuca
    lasiorhyncha (San Bernardino Mountains owl's clover)
    linariifolia (Narrow-leaved paintbrush)
    miniata ssp. miniata (Great red paintbrush)
    minor ssp. spiralis (Lesser paintbrush)
    mollis (Soft-leaved paintbrush)
    montigena (Heckard's paintbrush)
    nana (Dwarf alpine paintbrush)
    plagiotoma (Yellow paintbrush)
    subinclusa ssp. subinclusa (Longleaf paintbrush)
    tenuis (Hairy owl's clover)
Caulanthus
    amplexicaulis (Clasping-leaved caulanthus)
    anceps (Lemmon's mustard)
    cooperi (Cooper's jewelflower)
    coulteri (Coulter's jewelflower)
    crassicaulis (Thickstem wild cabbage)
    hallii (Hall's caulanthus)
    heterophyllus (Slender-pod jewelflower)
    inflatus (Desert candle)
    lasiophyllus (California mustard)
    major (Slender wild cabbage)
    simulans (Payson's jewelflower)
Ceanothus
    arboreus (Island ceanothus)
    cordulatus (Mountain whitethorn)
    crassifolius var. crassifolius (Hoaryleaf ceanothus)
    cuneatus var. cuneatus (Buckbrush)
    cyaneus (Lakeside ceanothus)
    greggii var. perplexans, see Ceanothus perplexans
    greggii var. vestitus, see Ceanothus pauciflorus
    integerrimus var. macrothyrsus (Deerbrush)
    leucodermis (Chaparral whitethorn)
    megacarpus var. megacarpus (Big-pod ceanothus)
    oliganthus var. oliganthus (Hairy ceanothus)
    palmeri (Palmer's ceanothus)
    papillosus (Wartleaf ceanothus)
    perplexans (Cupleaf ceanothus)
    pauciflorus (Mojave ceanothus)
    spinosus (Greenbark ceanothus)
    tomentosus (Woollyleaf ceanothus)
    verrucosus (Wartstem ceanothus)
Celtis reticulata (Western hackberry)
Centaurea
    benedictus (Blessed thistle)*
    maculosa, see Centaurea stoebe ssp. micranthos
    melitensis (Tocalote)*
    solstitialis (Yellow star thistle)*
    stoebe ssp. micranthos (Spotted knapweed)*
Centaurium venustum, see Zeltnera venusta
Centranthus ruber (Red valerian)*
Centromadia
    parryi ssp. australis (Southern tarplant)
    pungens ssp. laevis (Smooth tarplant)
    pungens ssp. pungens (Spikeweed)
Centrostegia thurberi (Thurber's spineflower)
Centunculus minimus, see Lysimachia minima
Cerastium
    fontanum ssp. vulgare (Perennial chickweed)*
    glomeratum (Mouse-ear chickweed)*
Cercidium
    floridum ssp. floridum, see Parkinsonia florida
    microphyllum. see Parkinsonia microphylla
Cercis occidentalis (Western redbud)
Cercocarpus
    betuloides var. betuloides (Birch-leaf mountain-mahogany)
    betuloides var. blancheae (Island mountain-mahogany)
    intricatus, see Cercocarpus ledifolius var. intricatus
    ledifolius var. intricatus (Little-leaved mountain-mahogany)
    ledifolius var. intermontanus (Curl-leaf mountain-mahogany)
    minutiflorus (San Diego mountain-mahogany)
    traskiae (Catalina Island mountain-mahogany)
Chaenactis
    artemisiifolia (White pincushion)
    carphoclinia var. carphoclinia (Pebble pincushion)
    douglasii var. douglasii (Dusty maidens)
    fremontii (Fremont's pincushion)
    glabriuscula var. glabriuscula (Yellow pincushion)
    glabriuscula var. orcuttiana (Orcutt's yellow pincushion)
    macrantha (Large-flowered pincushion)
    santolinoides (Santolina pincushion)
    stevioides (Desert pincushion)
    xantiana (Xantus pincushion)
Chaetadelpha wheeleri (Dune broom)
Chaetopappa ericoides (Rose heath)
Chamaebatia australis (Southern mountain misery)
Chamaebatiaria millefolium (Desert sweet)
Chamaesyce
    abramsiana, see Euphorbia ambramsiana
    albomarginata, see Euphorbia albomarginata
    arizonica, see Euphorbia arizonica
    melanadenia, see Euphorbia melanadenia
    micromera, see Euphorbia micromera
    ocellata ssp. arenicola, see Euphorbia ocellata ssp. arenicola
    parishii, see Euphorbia parishii
    parryi, see Euphorbia parryi
    pediculifera, see Euphorbia pediculifera
    polycarpa, see Euphorbia polycarpa
    prostrata, see Euphorbia prostrata
    serpyllifolia ssp. serpyllifolia, see Euphorbia serpyllifolia ssp. serpyllifolia
    setiloba, see Euphorbia setiloba
Chamerion angustifolium ssp. circumvagum (Fireweed)
Chamomilla suaveolens, see Matricaria matricarioides
Chasmanthe floribunda (South African cornflag)*
Cheilanthes
    clevelandii, see Myriopteris clevelandii
    cooperae, see Myriopteris cooperae
    covillei, see Myriopteris covillei
    feei, see Myriopteris gracilis
    newberryi, see Myriopteris newberryi
    parryi, see Myriopteris parryi
    viscida, see Myriopteris viscida
Chenopodium
    album (Lamb's quarters)*
    ambrosioides, see Dysphania ambrosioides
    atrovirens (Forest goosefoot)
    berlandieri (Pitseed goosefoot)
    botrys, see Dysphania botrys
    californicum (California goosefoot)
    desiccatum (Aridland goosefoot)
    fremontii (Fremont's goosefoot)
    hians (Gaping goosefoot)
    macrospermum (Coast goosefoot)*
    murale (Nettleleaf goosefoot)*
    pratericola (Meadow goosefoot)
Chilopsis linearis ssp. arcuata (Desert willow)
Chimaphila
    menziesii (Little prince's pine)
    umbellata (Pipsissewa)
Chloracantha spinosa var. spinosa (Spiny aster)
Chlorogalum
    parviflorum, see Hooveria parviflora
    pomeridianum var. pomeridianum (Soap plant)
Chloropyron
    maritimum ssp. maritimum (Salt marsh bird's beak)
    tecopense (Tecopa bird's beak)
Chondrilla juncea (Hogbite)*
Chorispora tenella (Crossflower)*
Chorizanthe
    brevicornu var. brevicornu (Brittle spineflower)
    corrugata (Wrinkled spineflower)
    fimbriata var. fimbriata (Fringed spineflower)
    fimbriata var. laciniata (Lace-fringed spineflower)
    leptotheca (Peninsular spineflower)
    membranacea (Pink spineflower)
    parryi var. fernandina (San Fernando Valley spineflower)
    procumbens (Prostrate spineflower)
    rigida (Rigid spineflower)
    spinosa (Mojave spineflower)
    staticoides (Turkish rugging)
    watsonii (Five-tooth spineflower)
    xanti var. leucotheca (Riverside spineflower)
    xanti var. xanti (Xantus' spineflower)
Chrysanthemum coronarium, see Glebionis coronaria
Chrysolepis sempervirens (Bush chinquapin)
Chrysothamnus
    nauseosus ssp. bernardinus, see Ericameria nauseosa var. bernardina
    nauseosus ssp. ceruminosus, see Ericameria nauseosa var. ceruminosa
    nauseosus ssp. consimilis, see Ericameria nauseosa var. oreophila
    nauseosus ssp. hololeucus, see Ericameria nauseosa var. hololeuca
    nauseosus ssp. mohavensis, see Ericameria nauseosa var. mohavensis
    paniculatus, see Ericameria paniculata
    parryi ssp. asper, see Ericameria parryi var. aspera
    teretifolius, see Ericameria teretifolia
    viscidiflorus ssp. viscidiflorus (Sticky-leaved rabbitbrush)
Chylismia
    brevipes ssp. brevipes (Yellow cups)
    cardiophyla ssp. cardiophylla (Heartleaf sun cup)
    cardiophylla ssp. robusta (Robust heartleaf sun cup)
    claviformis ssp. aurantiaca (Browneyes)
    claviformis ssp. claviformis (Mojave brown-eyed primrose)
    claviformis ssp. funerea (Death Valley brown-eyed primrose)
    claviformis ssp. lancifolia (Lanceleaf browneyes)
    claviformis ssp. peirsonii (Peirson's brown-eyed primrose)
    walkeri ssp. tortilis (Walker's sun cup)
Chylismiella pterosperma (Wingfruit sun cup)
Cichorium intybus (Chicory)*
Cirsium
    arizonicum var. tenuisectum (Red thistle)
    mohavense (Mojave thistle)
    neomexicanum (Desert thistle)
    nidulum, see Cirsium arizonicum var. tenuisectum
    occidentale var. californicum (California thistle)
    occidentale var. occidentale (Cobweb thistle)
    occidentale var. venustum (Venus thistle)
    scariosum var. citrinum (Southern meadow thistle)
    scariosum var. congdonii (Elk thistle)
    vulgare (Bull thistle)*
Cistanthe
    ambigua (Desert pot-herb)
    maritima (Seaside red maids)
Cistus
    creticus, see Cistus incanus
    incanus (Pink rock-rose)*
    ladanifer var. albiflorus (White-flowered rock-rose)*
    ladanifer var. maculatus (Crimson spot rock-rose)*
    Xpurpureus (Orchid rock-rose)*
Cladium californicum (California sawgrass)
Clarkia
    bottae (Punchbowl clarkia)
    cylindrica ssp. clavicarpa (Club-fruited speckled clarkia)
    cylindrica ssp. cylindrica (Speckled clarkia)
    dudleyana (Dudley's clarkia)
    epilobioides (Canyon clarkia)
    heterandra (Mountain clarkia)
    purpurea ssp. quadrivulnera (Purple clarkia)
    rhomboidea (Diamond-petalled clarkia)
    similis (Ramona clarkia)
    speciosa ssp. polyantha (Red spot clarkia)
    unguiculata (Elegant clarkia)
    xantiana ssp. xantiana (Gunsight fairyfan)
Claytonia
    exigua ssp. exigua (Little spring beauty)
    gypsophiloides (Gypsum spring beauty)
    parviflora ssp. parviflora (Narrow-leaf miner's lettuce)
    parviflora ssp. utahensis (Utah miner's lettuce)
    parviflora ssp. viridis (Green miner's lettuce)
    peirsonii ssp. peirsonii (Peirson's spring beauty)
    perfoliata ssp. mexicana (Southern miner's lettuce)
    perfoliata ssp. perfoliata (Miners' lettuce)
    rubra ssp. rubra (Redstem spring beauty)
Clematis
    lasiantha (Pipestems)
    ligusticifolia (Virgin's bower)
    pauciflora (Ropevine)
Cleome sparsifolia, see Carsonia sparsifolia
Cleomella
    arborea var. arborea (Bladderpod)
    arborea var. globosa (Round-fruited bladderpod)
    obtusifolia (Mojave stinkweed)
    oxystyloides (False-clover)
    sparsifolia (Naked cleome)
Clinopodium
    chandleri (San Diego satureja)
    douglasii (Yerba buena)
    mimuloides (Monkeyflower savory)
Cneoridium dumosum (Bushrue)
Cnicus benedictus, see Centaurea benedictus
Coleogyne ramosissima (Blackbrush)
Collinsia
    bartsiifolia var. davidsonii (Davidson's blue-eyed mary)
    callosa (Desert collinsia)
    childii (Child's collinsia)
    concolor (Southern Chinese houses)
    heterophylla var. austromontana (Downy Chinese houses)
    heterophylla var. heterophylla (Chinese houses)
    parryi (Parry's collinsia)
    parviflora (Small-flowered collinsia)
    tinctoria (Sticky Chinese houses)
    torreyi var. wrightii (Wright's collinsia)
Collomia
    grandiflora (Large-flowered collomia)
    linearis (Slenderleaf collomia)
Colutea arborescens (Bladder senna)*
Comandra umbellata ssp. californica (California bastard toadflax)
Comarostaphylis
    diversifolia ssp. diversifolia (Varied-leaf summer-holly)
    diversifolia ssp. planifolia (Flat-leaf summer-holly)
Condea emoryi (Desert lavender)
Conium maculatum (Poison hemlock)*
Constancea nevinii (Nevin's woolly sunflower)
Convolvulus
    arvensis (Bindweed)*
    simulans (Small-flowered morning glory)
Conyza
    bonariensis, see Erigeron bonariensis
    canadensis, see Erigeron canadensis
    coulteri, see Laennecia coulteri
    floribunda*, see Erigeron sumatrensis
Corallorhiza maculata (Spotted coralroot)
Cordylanthus
    maritimus ssp. maritimus, see Chloropyron maritimum ssp. maritimum
    nevinii (Nevin's bird's beak)
    orcuttianus, see Dicranostegia orcuttiana
    parviflorus (Purple bird's beak)
    rigidus ssp. rigidus (Stiffbranch bird's beak)
    rigidus ssp. setiger (Bristly bird's beak)
Coreopsis
    bigelovii, see Leptosyne bigelovii
    californica var. californica, see Leptosyne californica
    gigantea, see Leptosyne gigantea
    maritima, see Leptosyne maritima
Corethrogyne filaginifolia (California-aster)
Cornus
    nuttallii (Mountain dogwood)
    sericea ssp. sericea (American dogwood)
Coronopus didymus, see Lepidium didymum
Cortaderia selloana (Pampas grass)*
Cosmos bipinnatus (Mexican aster)*
Cotula
    australis (Australian brass buttons)*
    coronopifolia (Brass buttons)*
Crassula
    aquatica (Water pygmyweed)
    colligata ssp. lamprosperma (Australian pygmyweed)*
    connata (Pygmyweed)
    tillaea (Moss pygmyweed)*
Crepis
    acuminata (Tall hawksbeard)
    nana (Dwarf hawksbeard)
    occidentalis (Western hawksbeard)
Cressa truxillensis (Alkali weed)
Crocanthemum scoparium var. vulgare (Peak rush-rose)
Crossosoma
    bigelovii (Rock crossosoma)
    californicum (Catalina crossosoma)
Croton
    californicus (California croton)
    setiger (Doveweed)
    wigginsii (Wiggins's croton)
Cryptantha
    angustifolia, see Johnstonella angustifolia
    barbigera var. barbigera (Bearded cryptantha)
    barbigera var. fergusoniae (Ferguson's bearded cryptantha)
    cinerea var. abortiva, see Oreocarya abortiva
    circumscissa var. circumscissa, see Greeneocharis circumscissa var. circumscissa
    clevelandii (Cleveland's cryptantha)
    confertiflora, see Oreocarya confertiflora
    costata, see Johnstonella costata
    decipiens (Gravel cryptantha)
    dumetorum (Bush-loving cryptantha)
    flavoculata, see Oreoarya flavoculata
    gracilis (Slender cryptantha)
    holoptera, see Johnstonella holoptera
    intermedia var. intermedia (Large-flowered cryptantha)
    juniperensis (Rigid cryptantha)
    maritima (Guadalupe cryptantha)
    micrantha var. lepida, see Eremocarya lepida
    micrantha var. micrantha, see Eremocarya micrantha var. micrantha
    micromeres (Minute-flowered cryptantha)
    microstachys (Tejon cryptantha)
    mohavensis (Mojave cryptantha)
    muricata var. denticulata (Prickly-nut cryptantha)
    muricata var. jonesii (Jones' cryptantha)
    muricata var. muricata (Showy cryptantha)
    nevadensis (Nevada cryptantha)
    oxygona (Sharpnut cryptantha)
    pterocarya (Wingnut cryptantha)
    racemosa, see Johnstonella racemosa
    recurvata (Curvenut cryptantha)
    similis, see Greeneocharis similis
    simulans (Pinewoods cryptantha)
    tumulosa, see Oreocarya tumulosa
    utahensis (Scented cryptantha)
    virginensis (Virgin River cryptantha)
Cryptogramma acrostichoides (American rock-brake)
Cucurbita
    foetidissima (Calabazilla)
    palmata (Coyote melon)
Cupressus
    arizonica ssp. arizonica, see Hesperocyparis stephensonii
    forbesii, see Hesperocyparis forbesii
Cuscuta
    californica var. breviflora. see Cuscuta occidentalis
    californica var. californica (California dodder)
    californica var. papillosa (Papillate dodder)
    campestris (Western field dodder)
    denticulata (Desert dodder)
    occidentalis (Short-flowered California dodder)
    pacifica var. pacifica (Salt marsh dodder)
    pentagona, see Cuscuta campestris
    subinclusa (Canyon dodder)
Cusickiella douglasii (Alkali draba)
Cycladenia humilis var. venusta (Showy cycladenia)
Cylindropuntia
    acanthocarpa var. acanthocarpa (Buckhorn cholla)
    bernardina (Valley cholla)
    bigelovii (Jumping cholla)
    echinocarpa (Silver cholla)
    fosbergii (Fosberg's cholla)
    ganderi (Gander's cholla)
    munzii (Munz's cholla)
    prolifera (Coast cholla)
    ramosissima (Pencil cholla)
    wolfii (Wolf's cholla)
Cymopterus
    aboriginum (Spring-parsley)
    gilmanii (Gilman's cymopterus)
    multinervatus (Arizona springparsley)
Cynara cardunculus ssp. flavescens (Cardoon)*
Cynodon dactylon (Bermuda grass)*
Cynoglossum grande, see Adelinia grandis
Cyperus
    eragrostis (Tall flat sedge)
    involucratus (Umbrella plant)*
    laevigatus (Smooth flatsedge)
Cystopteris fragilis (Brittle fern)
Cytisus striatus (Portuguese broom)*
Dactylis glomerata (Orchard grass)*
Dalea
    mollis (Silky dalea)
    mollissima (Downy dalea)
    searlsiae (Searls' prairie clover)
Dasyochloa pulchella (Fluff grass)
Datisca glomerata (Durango root)
Datura
    discolor (Desert thornapple)
    stramonium (Jimsonweed)*
    wrightii (Sacred datura)
Daucus
    carota (Queen Anne's lace)
    pusillis (American wild carrot)
Dedeckera eurekensis (July gold)
Deinandra
    arida (Red Rock tarplant)
    clementina (Island tarplant)
    conjugens (Otay tarplant)
    fasciculata (Slender tarplant)
    kelloggii (Kellogg's tarplant)
    minthornii (Santa Susana tarplant)
    mohavensis (Mojave tarplant)
    pallida (Kern tarplant)
    paniculata (San Diego tarplant)
Delairea odorata (Cape-ivy)*
Delphinium
    cardinale (Scarlet larkspur)
    glaucum (Mountain larkspur)
    gypsophilum (Gypsum-loving larkspur)
    hansenii ssp. kernense (Kern larkspur)
    parishii ssp. pallidum (Pale larkspur)
    parishii ssp. parishii (Desert larkspur)
    parishii ssp. subglobosum (Colorado Desert larkspur)
    parryi ssp. parryi (Blue larkspur)
    patens ssp. hepaticoideum (Spreading larkspur)
    patens ssp. montanum (Mountain spreading larkspur)
Dendromecon
    harfordii (Channel Island tree poppy)
    rigida (Bush poppy)
Deschampsia elongata (Slender hairgrass)
Descurainia
    californica (Sierra tansy mustard)
    incana (Appressed-fruited mountain tansy mustard)
    incisa ssp. incisa (Mountain tansy mustard)
    pinnata ssp. brachycarpa (Western tansy mustard)
    pinnata ssp. glabra (Tansy mustard)
    sophia (Flix weed)*
Dicentra
    chrysantha, see Ehrendorferia chrysantha
    ochroleuca, see Ehrendorferia ochroleuca
Dichelostemma, see Dipterostemon
Dichondra occidentalis (Western dichondra)
Dicoria canescens (Desert dicoria)
Dicranostegia  orcuttiana (Orcutt's bird's beak)
Dieteria
    asteroides var. asteroides (Scrub aster)
    asteroides var. lagunensis (Laguna Mountains aster)
    canescens var. canescens (Hoary-aster)
    canescens var. leucanthemifolia (Desert hoary-aster)
    canescens var. ziegleri (Ziegler's aster)
Digitalis purpurea (Foxglove)*
Dimorphotheca ecklonis (African daisy)*
Diplacus
    aridus (Low bush monkeyflower)
    australis (Southern bush monkeyflower)
    bigelovii var. bigelovii (Bigelow's monkeyflower)
    bigelovii var. cuspidatus (Northern desert monkeyflower)
    bolanderi (Bolander's monkeyflower)
    brevipes (Yellow monkeyflower)
    calycinus (Southern Sierra bush monkeyflower)
    clevelandii (Cleveland's bush monkeyflower)
    congdonii (Congdon's monkeyflower)
    constrictus (Dense-fruited monkeyflower)
    fremontii (Fremont's monkeyflower)
    johnstonii (Johnston's monkeyflower)
    longiflorus (Hairy bush monkeyflower)
    parviflorus (Island bush monkeyflower)
    pictus (Calico monkeyflower)
    puniceus (Red bush monkeyflower)
    rupicola (Death Valley monkeyflower)
Dipterostemon
    capitatus ssp. capitatus (Blue dicks)
    capitatus ssp. pauciflorus (Few-flowered blue dicks)
Distichlis
    littoralis (Shore grass)
    spicata (Salt grass)
Ditaxis
    lanceolata (Narrow-leaf ditaxis)
    neomexicana (New Mexico ditaxis)
Dithyrea californica (Spectacle pod)
Dodecatheon, see Primula
Downingia
    bella (Spotted downingia)
    cuspidata (Toothed calicoflower)
Draba
    albertina (Slender draba)
    corrugata (Southern California draba)
    cuneifolia (California draba)
    saxosa (Southern California rock draba)
    verna (Spring draba)
Drymocallis
    cuneifolia var. ewanii (Ewan's cinquefoil)
    glandulosa var. glandulosa (Inland sticky cinquefoil)
    glandulosa var. reflexa (Double-toothed sticky cinquefoil)
    glandulosa var. viscida (Single-toothed sticky cinquefoil)
    glandulosa var. wrangelliana (Coastal sticky cinquefoil)
    lactea var. lactea (Nevada cinquefoil)
Dryopteris arguta (Coastal wood fern)
Duchesnea indica var. indica (Mock-strawberry)*
Dudleya
    abramsii ssp. affinis (San Bernardino Mountains dudleya)
    arizonica (Arizona chalk dudleya)
    attenuata ssp. orcuttii (Orcutt's dudleya)
    caespitosa (Sand-lettuce)
    candelabrum (Candleholder dudleya)
    cymosa ssp. agourensis (Agoura dudleya)
    cymosa ssp. crebrifolia (San Gabriel River dudleya)
    cymosa ssp. cymosa (Canyon dudleya)
    cymosa ssp. pumila (Low canyon dudleya)
    densiflora (San Gabriel Mountains dudleya)
    edulis (Ladies' fingers)
    greenei (Greene's dudleya)
    hassei, see Dudleya virens ssp. hassei
    lanceolata (Lanceleaf dudleya)
    multicaulis (Many-stemmed dudleya)
    pulverulenta (Chalk dudleya)
    saxosa ssp. aloides (Rock dudleya)
    traskiae (Santa Barbara Island dudleya)
    variegata (Variegated dudleya)
    virens ssp. hassei (Hasse's dudleya)
    viscida (Sticky dudleya)
Dysphania
    ambrosioides (Mexican-tea)*
    botrys (Jerusalem-oak goosefoot )*