Haloragaceae (Water-milfoil):

Myriophyllum sibiricum (Siberian water-milfoil)


Heliotropiaceae (Heliotropium):

Heliotropium curassavicum var. oculatum (Wild heliotrope)


Hydrangeaceae (Hydrangea):

Carpenteria californica (Bush anemone)*
Fendlerella utahensis (Utah fendlerbush)
Philadelphus microphyllus (Little-leaved mock orange)


Hydrocharitaceae (Waterweed):

Elodea nuttallii (Western waterweed)


Hydrophyllaceae (Waterleaf):

Emmenanthe penduliflora (Whispering bells)
Eriodictyon, now in family Namaceae
Eucrypta
    chrysanthemifolia var. bipinnatifida (Torrey's eucrypta)
    chrysanthemifolia var. chrysanthemifolia (Common eucrypta)
    micrantha (Small-flowered eucrypta)
Hesperochiron californicus (California hesperochiron)
Nama, now in family Namaceae
Nemophila
    maculata (Fivespot)
    menziesii var. integrifolia (Small-flower baby blue eyes)
    menziesii var. menziesii (Large-flower baby blue eyes)
    pedunculata (Meadow nemophila)
    pulchella var. pulchella (Eastwood's baby blue eyes)
    spatulata (Sierra nemophila)
Phacelia
    affinis (Limestone phacelia)
    anelsonii (Aven Nelson's phacelia)
    austromontana (Southern mountain phacelia)
    bicolor (Two-color phacelia)
    brachyloba (Yellow-throated phacelia)
    calthifolia (Caltha-leaved phacelia)
    campanularia var. campanularia (Desert bluebells)
    campanularia var. vasiformis (Funnel bluebells)
    cicutaria var. cicutaria (White caterpillar phacelia)
    cicutaria var. hispida (Caterpillar phacelia)
    cicutaria var. hubbyi, see Phacelia hubbyi
    ciliata (Great valley phacelia)
    congdonii (Congdon's phacelia)
    crenulata var. ambigua (Notch-leaf phacelia)
    crenulata var. crenulata (Cleftleaf wild heliotrope)
    crenulata var. minutiflora (Smallflower notchleaf phacelia)
    cryptantha (Hiddenflower phacelia)
    curvipes (Curved-stem phacelia)
    davidsonii (Davidson's phacelia)
    distans (Common phacelia)
    douglasii (Douglas phacelia)
    egena (Rock phacelia)
    exilis (Lavender windows)
    fremontii (Fremont's phacelia)
    grandiflora (Large-flowered phacelia)
    hastata var. hastata (Timberline phacelia)
    hubbyi (Hubby's phacelia)
    humilis var. dudleyi (Low phacelia)
    imbricata var. imbricata (Mountain phacelia)
    imbricata var. patula (Imbricate phacelia)
    insularis var. insularis (Northern Channel Islands phacelia)
    ivesiana (Ives' phacelia)
    lemmonii (Lemmon's phacelia)
    longipes (Longstalk phacelia)
    minor (Canterbury bells)
    mohavensis (Mojave phacelia)
    mutabilis (Changeable phacelia)
    nashiana (Charlotte's phacelia)
    neglecta (Alkali phacelia)
    pachyphylla (Thick-leaved phacelia)
    parryi (Parry's phacelia)
    pedicellata (Pedicellate phacelia)
    perityloides var. perityloides (Panamint phacelia)
    ramosissima (Branching phacelia)
    rotundifolia (Round-leaved phacelia)
    tanacetifolia (Tansy-leaved phacelia)
    vallis-mortae (Death Valley phacelia)
    viscida var. albiflora (White sticky phacelia)
    viscida var. viscida (Sticky phacelia)
Pholistoma
    auritum var. auritum (Fiesta flower)
    membranaceum (White fiesta flower)
Tricardia watsonii (Three-hearts)
Turricula, see family Boraginaceae


Hypericaceae (St. John's wort):

Hypericum
    anagalloides (Tinker's penny)
    formosum var. scouleri, see Hypericum scouleri
    scouleri (Scouler's St. John's wort)

Iridaceae (Iris):

Chasmanthe floribunda (South African cornflag)*
Iris
    douglasiana (Douglas's iris)
    hartwegii ssp. australis (Hartweg's iris)
    missouriensis (Western blue flag)
    pseudacorus (Yellow flag)*
Sisyrinchium
    bellum (Blue-eyed grass)
    elmeri (Yellow-eyed grass)
    funereum (Death Valley blue-eyed grass)
    halophilum (Nevada blue-eyed grass)
    idahoense var. occidentale (Idaho blue-eyed grass)


Isoetaceae (Quillwort):

Isoetes bolanderi (Bolander's quillwort)

Juglandaceae (Walnut):

Juglans californica (California black walnut)

Juncaceae (Rush):

Juncus
    acutus ssp. leopoldii (Spiny rush)
    balticus (Wire rush)
    bryoides (Moss rush)
    bufonius var. bufonius (Common toad rush)
    bufonius var. congestus (Clustered toad rush)
    bufonius var. occidentalis (Western toad rush)
    cooperi (Cooper's rush)
    covillei (Coville's rush)
    dubius (Mariposa rush)
    effusus ssp. pacificus (Pacific rush)
    macrandrus (Long-anthered rush) 
    macrophyllus (Long-leaved rush)
    mexicanus (Mexican rush)
    orthophyllus (Straightleaf rush)
    patens (Spreading rush)
    phaeocephalus var. paniculatus (Brown-headed rush)
    rugulosus (Wrinkled rush)
    saximontanus (Rocky Mountain rush)
    textilis (Basket rush)
    tiehmii (Tiehm's rush)
    xiphioides (Iris-leaved rush)
Luzula comosa (Hairy wood rush)


Juncaginaceae (Arrow-Grass):

Lilaea scilloides, see Triglochin scilloides
Triglochin scilloides (Flowering quillwort)


Krameriaceae (Krameria):

Krameria
    bicolor (White rhatany)
    erecta (Littleleaf rhatany)
    grayi, see Krameria bicolor

Lamiaceae (Mint):

Lauraceae (Laurel):

Umbellularia californica (California bay)


Lennoaceae (Lennoa):

Pholisma
    arenarium (Scaly-stemmed sand plant)
    sonorae (Sand food)


Liliaceae (Lily):

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)
Fritillaria
    biflora var. biflora (Chocolate lily)
    ojaiensis (Ojai fritillary)
    pinetorum (Pinewoods fritillary)
    striata (Striped adobe lily)
Lilium
    humboldtii ssp. ocellatum (Humboldt lily)
    pardalinum (Leopard lily)
    parryi (Lemon lily)

Limnanthaceae (Meadowfoam):

Limnanthes
    alba ssp. parishii (Parish's meadowfoam)
    gracilis ssp. parishii, see Limnanthes alba ssp. parishii

Linaceae (Flax):

Hesperolinon micranthum (Small-flowered dwarf flax)
Linum
    lewisii var. lewisii (Western blue flax)
    puberulum (Plains flax)
    usitatissimum (Common flax)*


Loasaceae (Loasa):

Eucnide
    rupestris (Annual rock-nettle)
    urens (Desert rock-nettle)
Mentzelia
    affinis (Yellow comet)
    albicaulis (Whitestem blazing star)
    congesta (Clustered blazing star)
    dispersa (Bushy blazing star)
    hirsutissima (Hairy blazing star)
    involucrata (Sand blazing star)
    jonesii (Jones' blazing star)
    laevicaulis (Giant blazing star)
    lindleyi (Lindley's blazing star)
    longiloba (Yerba amarilla)
    micrantha (Stickleaf)
    montana (Mountain blazing star)
    multiflora var. longiloba, see Mentzelia longiloba
    obscura (Pacific blazing star)
    oreophila (Inyo blazing star)
    polita (Polished blazing star)
    reflexa (Reflexed blazing star)
    veatchiana (Veatch's blazing star)
Petalonyx
    nitidus (Shinyleaf sandpaper plant)
    thurberi ssp. thurberi (Sandpaper plant)

Lythraceae (loosestrife):

Ammannia coccinea (Red ammannia)
Lythrum
    californicum (California loosestrife)
    hyssopifolia (Hyssop loosestrife)

Malvaceae (Mallow):

Abutilon
    abutiloides (Shrubby mallow)*
    palmeri (Palmer's mallow)
Ayenia compacta (California ayenia)
Eremalche
    exilis (White mallow)
    parryi ssp. kernensis (Kern mallow)
    rotundifolia (Desert five-spot)
Fremontodendron
    californicum (Flannel bush)
    mexicanum (Mexican flannel bush)
Hibiscus denudatus (Rock hibiscus)
Horsfordia
    alata (Pink velvet-mallow)
    newberryi (Newberry's velvet-mallow)
Lavatera
    assurgentiflora, see Malva assurgentiflora
    cretica, see Malva pseudolavatera
Malacothamnus
    clementinus (San Clemente Island bush mallow)
    davidsonii (Davidson's bush mallow)
    densiflorus (Many-flowered bush mallow)
    enigmaticus (Enigmatic bush mallow)
    fasciculatus var. fasciculatus (Bush mallow)
    fasciculatus var. nesioticus (Santa Cruz Island bush mallow)
    fremontii (Fremont's bush mallow)
    orbiculatus (Round-leaved bush mallow)
Malva
    assurgentiflora (Island mallow)
    neglecta (Common mallow)*
    nicaeensis (Bull mallow)*
    parviflora (Cheeseweed)*
    pseudolavatera (Cretan mallow)*
Malvella leprosa (Alkali mallow)
Sidalcea
    malviflora ssp. dolosa (Dwarf checkerbloom)
    malviflora ssp. malviflora (Island checkerbloom)
    malviflora ssp. sparsifolia, see Sidalcea sparsifolia
    pedata (Big Bear checkerbloom)
    sparsifolia (Few-leaved checkerbloom)
Sphaeralcea
    ambigua var. ambigua (Apricot mallow)
    ambigua var. rosacea (Rosy apricot mallow)
    ambigua var. rugosa (Desert globemallow)
    angustifolia (Narrow-leaved globemallow)
    coulteri (Coulter's globemallow)
    rusbyi var. eremicola (Rusby's desert mallow)


Marsileaceae (Marsilea):

Marsilea vestita ssp. vestita (Clover fern)


Martyniaceae (Unicorn-Plant):

Proboscidea althaeifolia (Desert unicorn plant)


Melanthiaceae (Trillium):

Toxicoscordion
    brevibracteatum (Desert zygadene)
    fremontii (Star lily)
    venenosum var. venenosum (Death camas)
Veratrum californicum var. californicum (Corn lily)
Zigadenus
    brevibracteatus, see Toxicoscordion brevibracteatum
    fremontii, see Toxicoscordion fremontii
    venenosus var. venenosus, see Toxicoscordion venenosum var. venenosum


Molluginaceae (Carpet-weed):

Mollugo cerviana (Threadstem carpet-weed)*


Montiaceae (Miner's lettuce):

Calandrinia
    ambigua, see Cistanthe ambigua
    breweri (Brewer's red maids)
    ciliata, see Calandrinia menziesii
    maritima, see Cistanthe maritima
    menziesii (Red maids)
Calyptridium
    monandrum (Sand cress)
    monospermum (One-seeded pussypaws)
    parryi var. parryi (Parry's pussypaws)
    pygmaeum (Pygmy pussypaws)
Cistanthe
    ambigua (Desert pot-herb)
    maritima (Seaside red maids)
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 (Miner's lettuce)
    rubra ssp. rubra (Redstem spring beauty)
Lewisia
    nevadensis (Sierra lewisia)
    pygmaea (Dwarf lewisia)
    rediviva var. minor (Bitterroot)
Montia
    chamissoi (Toad lily)
    fontana (Water chickweed)


Moraceae (Mulberry):

Ficus carica (Edible fig)*


Myricaceae (Wax-Myrtle):

Morella californica (California wax-myrtle)
Myrica californica, see Morella californica


Myrsinaceae (Myrsine):

Anagallis
    arvensis, see Lysimachia arvensis
    minima, see Lysimachia minima
Centunculus minimus, see Lysimchia minima
Lysimachia
    arvensis (Scarlet pimpernel)*
    minima (Common chaffweed)

Myrtaceae (Myrtle):

Eucalyptus globulus (Blue gum)*


Namaceae (Nama):

Eriodictyon
    crassifolium var. crassifolium (Thickleaf yerba santa)
    crassifolium var. nigrescens (Bicolored yerba santa)
    parryi (Poodle-dog bush)
    traskiae ssp. smithii (Trask's yerba santa)
    trichocalyx var. lanatum (San Diego yerba santa)
    trichocalyx var. trichocalyx (Hairy yerba santa)
Nama
    californic (California fiddleleaf)
    demissa var. covillei (Coville's purple mat)
    demissa var. demissa (Purple mat)
    pusillum (Small-leaved nama)
    rothrockii (Rothrock's nama)
    stenocarpa (Mud nama)

Nyctaginaceae (Four O'clock):

Abronia
    maritima (Red sand-verbena)
    nana var. covillei (Coville's dwarf abronia)
    pogonantha (Mojave sand-verbena)
    turbinata (White sand-verbena)
    umbellata var. umbellata (Pink sand-verbena)
    villosa var. aurita (Chaparral sand-verbena)
    villosa var. villosa (Desert sand-verbena)
Allionia
    incarnata var. incarnata (Trailing windmills)
    incarnata var. villosa (Hairy windmills)
Anulocaulis annulatus (Sticky ringstem)
Boerhavia
    coccinea (Scarlet spiderling)
    coulteri var. palmeri (Coulter's spiderling)
    intermedia, see Boerhavia triquetra var. intermedia
    triquetra var. intermedia (Slender spiderling)
    wrightii (Wright's spiderling)
Mirabilis
    albida (Dwarf four o'clock)
    bigelovii var. bigelovii, see Mirabilis laevis var. villosa
    bigelovii var. retrorsa, see Mirabilis laevis var. retrorsa
    coccinea (Red four o'clock)
    jalapa var. jalapa (Cultivated four o'clock)*
    laevis var. crassifolia (Wishbone bush)
    laevis var. retrorsa (Retrorse desert four o'clock)
    laevis var. villosa (Desert wishbone bush)
    multiflora var. pubescens (Giant four o'clock)
    pumila, see Mirabilis albida
    tenuiloba (Slender-lobed four o'clock)

Oleaceae (Olive):

Forestiera pubescens (Desert olive)
Fraxinus
    dipetala (California ash)
    velutina (Velvet ash)
Menodora
    scabra (Rough menodora)
    spinescens (Spiny menodora)

Onagraceae (Evening primrose):

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)
Chamerion angustifolium ssp. circumvagum (Fireweed)
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)
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)
Epilobium
    angustifolium ssp. circumvagum, see Chamerion angustifolium ssp. circumvagum
    brachycarpum (Field willow-herb)
    campestre (Smooth boisduvalia)
    canum ssp. canum (Hoary fuchsia)
    canum ssp. latifolium (California fuchsia)
    ciliatum ssp. ciliatum (Willow-herb)
    ciliatum ssp. glandulosum (Glandular willow-herb)
    densiflorum (Spike primrose)
    glaberrimum ssp. glaberrimum (Smooth willow-herb)
    hallianum (Hall's willow-herb)
    lactiflorum (Milkflower willow-herb)
    oregonense (Oregon willow-herb)
    pygmaeum, see Epilobium campestre
Eremothera
    boothii ssp. condensata (Booth's clustered evening primrose)
    boothii ssp. decorticans (Booth's shredding evening primrose)
    boothii ssp. desertorum (Booth's desert evening primrose)
    boothii ssp. intermedia (Booth's intermediate evening primrose)
    chamaenerioides (Longfruit sun cup)
    refracta (Narrow-leaf suncup)
Eulobus californicus (California sun cup)
Gaura
    coccinea, see Oenothera suffrutescens
    sinuata, see Oenothera sinuosa
Gayophytum
    diffusum ssp. parviflorum (Small-flowered groundsmoke)
    heterozygum (Zig-zag groundsmoke)
    oligospermum (Pinegrove groundsmoke)
Ludwigia peploides (Yellow water-weed)
Oenothera
    avita ssp. eurekensis (Eureka Dunes evening primrose)
    cespitosa ssp. marginata (Tufted evening primrose)
    californica ssp. avita (Desert evening primrose)
    californica ssp. californica (California evening primrose)
    cavernae (Cave evening primrose)
    deltoides ssp. deltoides (Basket evening primrose)
    elata ssp. hirsutissima (Hairy evening primrose)
    elata ssp. hookeri (Hooker's evening primrose)
    primiveris (Large yellow primrose)
    rosea (Rose evening primrose)*
    sinuosa (Wavyleaf bee blossom)*
    suffrutescens (Scarlet gaura)
Tetrapteron palmeri (Palmer's sun cup)

Ophioglossaceae (Adder's-tongue):

Botrychium crenulatum (Scalloped moonwort)
Ophioglossum californicum (California adder's-tongue)


Orchidaceae (Orchid):

Corallorhiza maculata (Spotted coralroot)
Epipactis gigantea (Stream orchid)
Listera convallarioides (Twayblade)
Piperia
    cooperi (Rein orchid)
    elongata (Dense-flowered rein orchid)
    transversa (Royal rein orchid)
    unalascensis (Alaska rein orchid)
Platanthera
    dilatata var. leucostachys (White-flowered bog orchid)
    leucostachys, see Platanthera dilatata var. leucostachys
    sparsiflora (Sparse-flowered bog orchid)