Abies concolor (White fir)
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)
Abutilon
    abutiloides (Shrubby mallow)*
    palmeri (Palmer's mallow)
Acacia
    baileyana (Cootamundra wattle)*
    farnesiana var. farnesiana, see Vachellia farnesiana var. farnesiana
    greggii, see Senegalia greggii
    longifolia (Golden wattle)*
Acalypha californica (California copperleaf)
Acamptopappus
    shockleyi (Shockley's goldenheads)
    sphaerocephalus var. hirtellus (Hairy goldenheads)
    sphaerocephalus var. sphaerocephalus (Goldenheads)
Acanthomintha
    ilicifolia (San Diego thornmint)
    obovata ssp. cordata (Heartleaf thornmint)
Acanthoscyphus
    parishii var. goodmaniana (Cushenbury oxytheca)
    parishii var. parishii (Parish's oxytheca)
Acer
    glabrum var. diffusum (Mountain maple)
    macrophyllum (Big-leaf maple)
    negundo (Box elder)
Achillea millefolium (Yarrow)
Achnatherum
    aridum. see Stipa arida
    coronatum, see Stipa coronata
    diegoense, see Stipa diegoensis
    hymenoides, see Stipa hymenoides
    occidentale var. occidentale, see Stipa occidentalis var. occidentalis
    parishii, see Stipa parishii var. parishii
    speciosum, see Stipa speciosa
Achyrachaena mollis (Blow wives)
Achyronychia cooperi (Frostmat)
Acmispon
    americanus var. americanus (Spanish clover)
    argophyllus var. adsurgens (San Clemente Island bird's-foot trefoil)
    argophyllus var. argophyllus (Silver lotus)
    argophyllus var. niveus (Santa Cruz Island bird's-foot trefoil)
    argyraeus var. argyraeus (Canyon bird's-foot trefoil)
    argyraeus var. multicaulis (Scrub lotus)
    brachycarpus (Hill lotus)
    dendroideus var. dendroideus (Island deerweed)
    dendroideus var. veatchii (San Miguel Island deerweed)
    denticulatus (River bar bird's-foot trefoil)
    glaber var. brevialatus (Short-winged deerweed)
    glaber var. glaber (Common deerweed)
    grandiflorus var. grandiflorus (Large-flowered lotus)
    haydonii (Pygmy lotus)
    heermannii var. heermannii (Heermann's lotus)
    maritimus var. brevivexillus (Short-bannered coastal lotus)
    maritimus var. maritimus (Coastal lotus)
    micranthus (Small-flowered lotus)
    nevadensis var. davidsonii (Davidson's lotus)
    nevadensis var. nevadensis (Sierra Nevada lotus)
    procumbens var. procumbens (Silky deerweed)
    rigidus (Desert rock pea)
    strigosus (Strigose lotus)
    wrangelianus (California lotus)
Acourtia microcephala (Sacapellote)
Actaea rubra (Red baneberry)
Adelinia grandis (Grand hound's tongue)
Adenophyllum
    cooperi (Cooper's dyssodia)
    porophylloides (San Felipe dyssodia)
Adenostoma
    fasciculatum var. fasciculatum (Chamise)
    fasciculatum var. obtusifolium (San Diego chamise)
    sparsifolium (Red shanks or ribbon bush)
Adiantum
    aleuticum (Five-finger fern)
    capillus-veneris (Maidenhair fern)
    jordanii (California maidenhair fern)
Adolphia californica (California adolphia)
Aegilops cylindrica (Jointed goatgrass)*
Aesculus californica (California buckeye)
Agastache urticifolia (Giant hyssop)
Agave
    americana (Century plant)*
    deserti var. deserti (Desert agave)
    deserti var. simplex (Single-rosetted desert agave)
    shawii var. shawii (Shaw's agave)
    utahensis (Utah agave)
Ageratina
    adenophora (Thoroughwort)*
    herbacea (Fragrant snakeroot)
    occidentalis (Western snakeroot)
Agoseris
    grandiflora var. grandiflora (Mountain dandelion)
    heterophylla var. heterophylla (Annual mountain dandelion)
    retrorsa (Spearleaf mountain dandelion)
Agropyron
    cristatum ssp. pectinatum (Desert crested wheat grass)*
    desertorum, see cristatum ssp. pectinatum
Agrostis
    idahoensis (Idaho bentgrass)
    pallens (Seashore bentgrass)
    viridis, see Polypogon viridis
Ailanthus altissima (Tree of heaven)*
Aliciella
    hutchinsifolia (Desert pale gilia)
    latifolia ssp. latifolia (Broad-leaf gilia)
    leptomeria (Great Basin gilia)
    ripleyi (Ripley's aliciella)
    triodon (Sand gilia)
Alisma plantago-aquatica, see Alisma triviale
Alisma triviale (Water plantain)
Allenrolfea occidentalis (Iodine bush)
Allionia
    incarnata var. incarnata (Trailing windmills)
    incarnata var. villosa (Hairy windmills)
Allium
    amplectens (Narrow-leaved onion)
    atrorubens var. cristatum (Crested onion)
    burlewii (Burlew's onion)
    campanulatum (Sierra onion)
    fimbriatum var. fimbriatum (Fringed onion)
    haematochiton (Red-skinned onion)
    howellii var. clokeyi (Mt. Pinos onion)
    lacunosum var. davisiae (Davis's pitted onion)
    monticola (San Bernardino mountain onion)
    nevadense (Nevada onion)
    parryi (Parry's fringed onion)
    peninsulare var. peninsulare (Peninsular onion)
    praecox (Early onion)
Allophyllum
    divaricatum (Purple false-gilia)
    gilioides ssp. gilioides (Dense false-gilia)
    gilioides ssp. violaceum (Violet false-gilia)
    glutinosum (Sticky false-gilia)
    integrifolium (White false-gilia)
Almutaster pauciflorus (Alkali marsh aster)
Alnus rhombifolia (White alder)
Alopecurus aequalis var. aequalis (Shortawn foxtail)
Aloysia wrightii (Wright's beebrush)
Amaranthus
    albus (Pigweed amaranth)*
    californicus (California amaranth)
    fimbriatus (Fringed amaranth)
    torreyi (Torrey's amaranth)
Amauriopsis dissecta, see Hymenothrix dissecta
Amblyopappus pusillus (Coastweed)
Ambrosia
    acanthicarpa (Annual bur-sage)
    chamissonis (Silver beach bur)
    chenopodiifolia (Goosefoot bur-sage)
    dumosa (Burrobush)
    eriocentra (Woolly bur-sage)
    ilicifolia (Holly-leaved bur-sage)
    psilostachya (Western ragweed)
    pumila (San Diego ambrosia)
    salsola var. salsola (Cheesebush)
Amelanchier utahensis (Utah serviceberry)
Ammannia coccinea (Red ammannia)
Amorpha
    californica var. californica (California false-indigo)
    fruticosa (Western false-indigo)
Amphipappus fremontii var. fremontii (Chaffbush)
Amsinckia
    eastwoodiae (Eastwood's fiddleneck)
    intermedia (Common fiddleneck)
    retrorsa (Rigid fiddleneck)
    spectabilis var. spectabilis (Seaside fiddleneck)
    tessellata var. gloriosa (Bristly fiddleneck)
    tessellata var. tessellata (Checker fiddleneck)
Amsonia tomentosa (Woolly amsonia)
Anagallis
    arvensis, see Lysimachia arvensis
    minima, see Lysimachia minima
Andropogon glomeratus var. scabriglumis (Southwestern bushy bluestem)
Androsace septentrionalis (Pygmy-flower rockjasmine)
Anemone tuberosa (Desert windflower)
Anemopsis californica (Yerba mansa)
Angelica
    capitellata (Ranger's buttons)
    lineariloba (Soda straw)
    tomentosa (Woolly angelica)
Anisocoma acaulis (Scalebud)
Antennaria
    dimorpha (Low pussytoes)
    media (Alpine pussytoes)
    rosea ssp. confinis (Rosy pussytoes)
Anthemis
    arvensis (Corn chamomile)*
    cotula (Mayweed)*
Anthriscus caucalis (Bur-chervil)*
Antirrhinum
    confertiflorum (Ghost flower)
    coulterianum (White snapdragon)
    filipes (Desert twining snapdragon)
    kelloggii (Twining snapdragon)
    mohavea (Lesser mohavea)
    multiflorum, see Antirrhinum thompsonii
    nuttallianum ssp. nuttallianum (Violet snapdragon)
    thompsonii (Rose snapdragon)
Anulocaulis annulatus (Sticky ringstem)
Aphanes occidentalis (Western lady's mantle)
Aphyllon
    californicum ssp. feudgei (California broomrape)
    cooperi (Cooper's broomrape)
    corymbosum (Flat-topped broomrape)
    franciscanum (Franciscan broomrape)
    parishii ssp. brachylobum (Short-lobed broomrape)
    parishii ssp. parishii (Parish's broomrape)
    purpureum (Naked broomrape)
    tuberosum (Chaparral broomrape)
    validum (Rock Creek broomrape)
    vallicolum (Valley broomrape)
Apiastrum angustifolium (Wild celery)
Apium graveolens (Common celery)*
Apocynum
    androsaemifolium (Spreading dogbane)
    cannabinum (Hemp dogbane)
Aptenia cordifolia (Baby sun rose)*
Aquilegia formosa (Columbine)
Arabidopsis thaliana (Mouse-ear cress)*
Arabis
    glabra, see Turritis glabra
    holboelii var. pinetorum, see Boechera pinetorum
    parishii, see Boechera parishii
    perennans, see Boechera perennans
    platysperma var. platysperma, see Boechera platysperma
    pulchra var. gracilis, see Boechera xylopoda
    pulchra var. pulchra, see Boechera pulchra
    rectissima, see Boechera rectissima
    repanda, see Boechera repanda
    shockleyi, see Boechera shockleyi
    sparsiflora var. arcuata, see Boechera arcuata
    sparsiflora var. californica. see Boechera californica
Aralia californica (California aralia)
Arbutus menziesii (Pacific madrone)
Arceuthobium campylopodum (Pine dwarf mistletoe)
Arctomecon merriamii (Bear poppy)
Arctostaphylos
    catalinae (Santa Catalina Island manzanita)
    confertiflora (Santa Rosa Island manzanita)
    gabrielensis, see Arctostaphylos glandulosa ssp. gabrielensis
    glandulosa ssp. adamsii (Adams' manzanita)
    glandulosa ssp. crassifolia (Del Mar manzanita)
    glandulosa ssp. gabrielensis (San Gabriel manzanita)
    glandulosa ssp. glandulosa (Eastwood manzanita)
    glandulosa ssp. glaucomollis, see Arctostaphylos glandulosa ssp. mollis
    glandulosa ssp. mollis (Transverse Range manzanita)
    glandulosa ssp. zacaensis, see Arctostaphylos glandulosa ssp. glandulosa
    glauca (Big-berry manzanita)
    insularis (Island manzanita)
    otayensis (Otay manzanita)
    parryana ssp. desertica (Desert manzanita)
    parryana ssp. parryana (Parry's manzanita)
    parryana ssp. tumescens (Interior manzanita)
    patula (Greenleaf manzanita)
    pringlei ssp. drupacea (Pink-bracted manzanita)
    pungens (Mexican manzanita)
    purissima (La purisima manzanita)
    rainbowensis (Rainbow manzanita)
    viridissima (McMinn's manzanita)
Arenaria
    kingii, see Eremogone kingii
    lanuginosa var. saxosa (Spreading sandwort)
    macradenia var. macradenia, see Eremogone macradenia var. macradenia
    ursina, see Eremogone ursina
Argemone
    corymbosa (Mojave prickly poppy)
    munita (Chicalote)
Argyrochosma jonesii (Jones' cloak fern)
Arida arizonica, see Leucosyris arida
Aristida
    adscensionis (Three-awn)
    purpurea var. nealleyi (Nealley three-awn)
Armeria maritima ssp. californica (California sea-pink)
Arnica
    chamissonis (Meadow arnica)
    mollis (Soft arnica)
Artemisia
    bigelovii (Flat sagebrush)
    californica (California sagebrush)
    douglasiana (Mugwort)
    dracunculus (Wild tarragon)
    ludoviciana ssp. incompta (Mountain wormwood)
    ludoviciana ssp. ludoviciana (Silver wormwood)
    nesiotica (Island sagebrush)
    nova (Black sagebrush)
    palmeri (Palmer's sagewort)
    rothrockii (Rothrock's sagebrush)
    spinescens (Budsage)
    tridentata ssp. parishii (Parish's sagebrush)
    tridentata ssp. tridentata (Basin sagebrush)
    tridentata ssp. vaseyana (Mountain sagebrush)
Arthrocnemum subterminale (Glasswort)
Arundo donax (Giant reed)*
Asclepias
    albicans (White-stemmed milkweed)
    californica (California milkweed)
    eriocarpa (Woolly-fruited milkweed)
    erosa (Desert milkweed)
    fascicularis (Narrow-leaved milkweed)
    nyctaginifolia (Mojave milkweed)
    subulata (Rush milkweed)
    vestita (Woolly milkweed)
Asparagus asparagoides (African asparagus fern)*
Asphodelus fistulosus (Onionweed)*
Aspidotis californica (California lace fern)
Aster
    alpigenus var. andersonii, see Oreostemma alpigenus var. andersonii
    ascendens, see Symphyotrichum ascendens
    bernardinus, see Symphyotrichum defoliatum
    chilensis, see Symphyotrichum chilense
    greatae, see Symphyotrichum greatae
    lanceolatus var. hesperius, see Symphyotrichum lanceolatum var. hesperium
    occidentalis var. occidentalis, see Symphyotrichum spathulatum var. spathulatum
    subulatus var. ligulatus, see Symphyotrichum subulatum var. paviflorum
Astragalus
    albens (Cushenbury milkvetch)
    allochrous var. playanus (Playa milkvetch)
    aridus (Annual desert milkvetch)
    bicristatus (Crested milkvetch)
    brauntonii (Braunton's rattleweed)
    calycosus var. calycosus (Torrey's milkvetch)
    cimae var. cimae (Cima milkvetch)
    cimae var. sufflatus (Inflated cima milkvetch)
    coccineus (Scarlet milkvetch)
    crotalariae (Salton milkvetch)
    curtipes (San Luis Obispo milkvetch)
    didymocarpus var. didymocarpus (Two-seeded milkvetch)
    didymocarpus var. dispermus (Dwarf white milkvetch)
    douglasii var. douglasii (Douglas's milkvetch)
    douglasii var. parishii (Parish's milkvetch)
    filipes (Narrowpod locoweed)
    gambelianus (Gambel's dwarf milkvetch)
    gilmanii (Gilman's milkvetch)
    layneae (Layne's locoweed)
    lentiginosus var. borreganus (Borrego milkvetch)
    lentiginosus var. fremontii (Fremont's milkvetch)
    lentiginosus var. micans (Shining milkvetch)
    lentiginosus var. semotus (White Mountains milkvetch)
    lentiginosus var. sierrae (Bear Valley milkvetch)
    lentiginosus var. variabilis (Varied milkvetch)
    leucolobus (Bear Valley woollypod)
    magdalenae var. peirsonii (Peirson's milkvetch)
    miguelensis (San Miguel milkvetch)
    minthorniae var. villosus (Minthorn's milkvetch)
    mohavensis var. mohavensis (Mojave milkvetch)
    newberryi var. newberryi (Newberry's rattleweed)
    nutans (Providence Mountains milkvetch)
    oophorus var. oophorus (Egg milkvetch)
    pachypus var. pachypus (Thickpod milkvetch)
    palmeri (Palmer's milkvetch)
    panamintensis (Panamint milkvetch)
    platytropis (Broad-keeled milkvetch)
    pomonensis (Pomona locoweed)
    preussii (Preuss's milkvetch)
    purshii var. lectulus (Pursh's milkvetch)
    purshii var. tinctus (Woollypod milkvetch)
    pycnostachyus var. lanosissimus (Ventura marsh milkvetch)
    sabulonum (Gravel milkvetch)
    serenoi var. shockleyi (Naked milkvetch)
    tidestromii (Tidestrom's milkvetch)
    tricarinatus (Triple-ribbed milkvetch)
    trichopodus var. lonchus (Coast locoweed)
    trichopodus var. phoxus (Santa Barbara milkvetch)
    whitneyi var. whitneyi (Whitney's locoweed)
Astrolepis cochisensis (Scaly cloak fern)
Athyrium filix-femina var. cyclosorum (Lady fern)
Athysanus pusillus (Dwarf athysanus)
Atrichoseris platyphylla (Gravel ghost)
Atriplex
    amnicola (Swamp saltbush)*
    argentea (Silverscale saltbush)
    canescens var. canescens (Four-wing saltbush)
    canescens var. laciniata (Caleb saltbush)
    canescens var. linearis (Slenderleaf saltbush)
    confertifolia (Shadscale saltbush)
    coulteri (Coulter's saltbush)
    covillei, see Stutzia covillei
    elegans var. fasciculata (Wheelscale saltbush)
    glauca (Waxy saltbush)*
    hymenelytra (Desert-holly)
    lentiformis (Quailbush)
    leucophylla (Beach saltbush)
    pacifica (Pacific saltbush)
    parryi (Parry's saltbush)
    phyllostegia, see Atriplex covillei
    polycarpa (Cattle spinach)
    prostrata (Arrowleaf saltbush)*
    semibaccata (Australian saltbush)*
    torreyi var. torreyi (Torrey's saltbush)
    triangularis, see Atriplex prostrata
    watsonii (Watson's saltbush)
Avena
    barbata (Slender oats)*
    fatua (Common wild oats)*
Ayenia compacta (California ayenia)
Azolla filiculoides (Pacific mosquito fern)
Baccharis
    brachyphylla (Shortleaf baccharis)
    douglasii, see Baccharis glutinosa
    emoryi, see Baccharis salicina
    glutinosa (Salt marsh baccharis)
    malibuensis (Malibu baccharis)
    pilularis ssp. consanguinea (Coyote brush)
    plummerae ssp. plummerae (Plummer's baccharis)
    salicifolia ssp. salicifolia (Mulefat)
    salicina (Willow baccharis)
    sarothroides (Broom baccharis)
    sergiloides (Desert baccharis)
    vanessae (Encinitas baccharis)
Bahia
    dissecta, see Amauriopsis dissecta
    neomexicana, see Picradeniopsis multiflora
Bahiopsis
    laciniata (San Diego County goldeneye)
    parishii (Parish's goldeneye)
    reticulata (Mojave goldeneye)
Baileya
    multiradiata (Desert marigold)
    pauciradiata (Lax flower)
    pleniradiata (Woolly marigold)
Balsamorhiza deltoidea (Deltoid balsamroot)
Barbarea orthoceras (Winter cress)
Bassia hyssopifolia (Five-hook bassia)*
Batis maritima (Saltwort)
Bebbia juncea var. aspera (Sweetbush)
Bellis perennis (English daisy)*
Berberis
    aquifolium var. repens (Creeping grape holly)
    fremontii (Fremont's barberry)
    nevinii (Nevin's barberry)
    pinnata ssp. pinnata (California barberry)
Bergerocactus emoryi (Golden-spined cereus)
Bernardia incana (Bernardia)
Berula erecta (Water parsnip)
Beta vulgaris ssp. maritima (Sea beet)*
Bidens
    laevis (Smooth beggar-ticks)
    pilosa (Common beggar-ticks)*
Bistorta bistortoides (Western bistort)
Bituminaria bituminosa (Pitch trefoil)*
Blennosperma nanum var. nanum (Yellow carpet)
Bloomeria
    clevelandii (Cleveland's muilla)
    crocea var. crocea (Golden stars)
    crocea var. montana (Mountain golden stars)
Boechera
    arcuata (Arching rock-cress)
    californica (California rock-cress)
    parishii (Parish's rock-cress)
    perennans (Perennial rock-cress)
    platysperma (Broad-seeded rock-cress)
    pulchra (Beautiful rock-cress)
    rectissima (Bristly-leaved rock-cress)
    repanda (Yosemite rock-cress)
    retrofracta X (Mountain rock-cress)
    shockleyi (Shockley's rock-cress)
    xylopoda (Slender beautiful rock-cress)
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)
Bolboschoenus maritimus ssp. paludosus (Marsh bulrush)
Boschniakia strobilacea, see Kopsiopsis strobilacea
Bothriochloa barbinodis (Cane beardgrass)
Botrychium crenulatum (Scalloped moonwort)
Bouteloua
    aristidoides var. aristodoides (Needle grama)
    curtipendula (Side-oats grama)
    eriopoda (Black grama)
    gracilis (Blue grama)
    trifida (Red grama)
Bowlesia incana (Bowlesia)
Boykinia
    occidentalis (Coast boykinia)
    rotundifolia (Round-leaved boykinia)
Brachypodium distachyon (Purple false-brome)*
Brandegea bigelovii (Brandegea)
Brassica
    fruticulosa (Mediterranean cabbage)*
    nigra (Black mustard)*
    rapa (Field mustard)*
    tournefortii (Saharan mustard)*
Brickellia
    arguta var. arguta, see Brickellia atractyloides var. arguta
    atractyloides var. arguta (Spearleaf brickellbush)
    californica (California brickellbush)
    desertorum (Desert brickellbush)
    frutescens (Shrubby brickellbush)
    incana (Woolly brickellbush)
    knappiana (Knapp's brickellbush)
    longifolia var. multiflora (Gum-leaved brickellbush)
    microphylla var. microphylla (Little-leaved brickellbush)
    multiflora, see Brickellia longifolia var. multiflora
    nevinii (Nevin's brickellbush)
    oblongifolia var. linifolia (Narrow-leaved brickellbush)
Brodiaea
    elegans (Harvest brodiaea)
    filifolia (Thread-leaved brodiaea)
    orcuttii (Orcutt's brodiaea)
    santarosae (Santa Rosa basalt brodiaea)
    terrestris ssp. kernensis (Earth brodiaea)
Bromus
    berteroanus (Chilean chess)
    carinatus var. carinatus, see Bromus sitchensis var. carinatus
    carinatus var. marginatus, see Bromus sitchensis var. marginatus
    carinatus var. maritimus, see Bromus sitchensis var. maritimus
    diandrus (Ripgut brome)*
    hallii (Hall's brome)
    hordeaceus (Soft chess)*
    rubens (Red brome)*
    sitchensis var. carinatus (California brome)
    sitchensis var. marginatus (Mountain brome)
    sitchensis var. maritimus (Seaside brome)
    tectorum (Cheat grass)*
    trinii, see Bromus berteroanus
Buddleja utahensis (Panamint butterfly bush)
Bursera microphylla (Elephant tree)