| Abutilon theophrasti | velvet-leaf |
| Acacia baileyana | Cootamundra wattle |
| Acacia dealbata | silver wattle |
| Acacia longifolia | golden wattle |
| Acacia melanoxylon | blackwood acacia |
| Acacia paradoxa | kangaroothorn |
| Acacia redolens | |
| Acacia retinodes | everblooming acacia |
| Acacia verticillata | star acacia |
| Acaena californica | California sheepburr |
| Acanthomintha lanceolata | Santa Clara thornmint |
| Acer campestre | hedge maple |
| Acer macrophyllum | big-leaf maple |
| Acer negundo | box elder |
| Achillea millefolium | yarrow |
| Achyrachaena mollis | blow-wives |
| Acmispon americanus var. americanus | Spanish-clover |
| Acmispon brachycarpus | woolly trefoil |
| Acmispon glaber var. glaber | California broom |
| Acmispon parviflorus | least trefoil |
| Acmispon strigosus | |
| Acmispon wrangelianus | common trefoil |
| Actaea rubra | baneberry |
| Adelinia grandis | hound's tongue |
| Adenostoma fasciculatum | chamise |
| Aesculus californica | California buckeye |
| Ageratina adenophora | |
| Agoseris grandiflora var. grandiflora | perennial |
| Agoseris heterophylla var. cryptopleura | annual |
| Agoseris heterophylla var. heterophylla | |
| Agoseris retrorsa | |
| Ailanthus altissima | tree of heaven |
| Allenrolfea occidentalis | iodine bush |
| Allophyllum divaricatum | purple false gilia |
| Allophyllum gilioides subsp. gilioides | dense false gilia |
| Allophyllum gilioides subsp. violaceum | |
| Alnus rhombifolia | white alder |
| Alnus rubra | red alder |
| Amaranthus albus | pigweed |
| Amaranthus blitoides | tumbleweed amaranth |
| Amaranthus californicus | California amaranth |
| Amaranthus deflexus | |
| Amaranthus hybridus | |
| Amaranthus powellii | |
| Amaranthus retroflexus | rough pigweed |
| Ambrosia chamissonis | beach-bur |
| Ambrosia psilostachya | western ragweed |
| Amelanchier utahensis | service-berry |
| Ammannia coccinea | |
| Amsinckia eastwoodiae | |
| Amsinckia grandiflora | large-flowered fiddleneck |
| Amsinckia intermedia | fiddleneck |
| Amsinckia lunaris | bent-flower fiddleneck |
| Amsinckia lycopsoides | |
| Amsinckia menziesii | rancher's fireweed |
| Amsinckia tessellata var. gloriosa | |
| Amsinckia tessellata var. tessellata | devil's lettuce |
| Amsinckia vernicosa | |
| Anaphalis margaritacea | pearly everlasting |
| Ancistrocarphus filagineus | woolly fishhook |
| Androsace elongata subsp. acuta | |
| Angelica californica | |
| Anisocarpus madioides | |
| Anthemis cotula | mayweed, dog-fennel |
| Anthriscus caucalis | bur-chervil |
| Antirrhinum kelloggii | |
| Antirrhinum majus | snapdragon |
| Antirrhinum thompsonii | Sierra snapdragon |
| Antirrhinum vexillocalyculatum subsp. vexillocalyculatum | |
| Aphanes occidentalis | western lady's mantle |
| Aphyllon californicum subsp. jepsonii | |
| Aphyllon epigalium subsp. epigalium | |
| Aphyllon franciscanum | yellow clustered broom-rape, Franciscan broom-rape |
| Aphyllon pinorum | pinewoods broom-rape |
| Aphyllon purpureum | naked broom-rape |
| Aphyllon tuberosum | bulbous broom-rape |
| Aphyllon vallicola | hemp broom-rape |
| Apiastrum angustifolium | |
| Apium graveolens | celery |
| Apium nodiflorum | |
| Apocynum androsaemifolium | dogbane |
| Apocynum cannabinum | Indian-hemp |
| Aquilegia eximia | |
| Aquilegia formosa | |
| Arabidopsis thaliana | mouse-ear cress |
| Aralia californica | elk-clover |
| Arbutus menziesii | Pacific madrone |
| Arceuthobium campylopodum | western dwarf mistletoe |
| Arctostaphylos auriculata | Mt. Diablo manzanita |
| Arctostaphylos crustacea subsp. crustacea | |
| Arctostaphylos glandulosa subsp. glandulosa | Eastwood manzanita |
| Arctostaphylos glauca | greatberry manzanita |
| Arctostaphylos manzanita subsp. laevigata | Contra Costa manzanita |
| Arctostaphylos manzanita subsp. manzanita | |
| Arctostaphylos pallida | pallid manzanita |
| Argemone munita | prickly poppy |
| Argyranthemum foeniculaceum | |
| Arnica discoidea | |
| Artemisia biennis | biennial wormwood |
| Artemisia californica | California sagebrush |
| Artemisia douglasiana | mugwort |
| Artemisia dracunculus | tarragon |
| Arthrocnemum subterminale | Parish's glasswort |
| Asclepias californica | California milkweed |
| Asclepias cordifolia | purple milkweed |
| Asclepias fascicularis | narrow-leaf milkweed |
| Asclepias speciosa | milkweed |
| Astragalus asymmetricus | San Joaquin milkvetch |
| Astragalus didymocarpus var. didymocarpus | two-seeded milkvetch |
| Astragalus gambelianus | little blue loco |
| Astragalus tener var. tener | alkali milkvetch |
| Athysanus pusillus | |
| Athysanus unilateralis | |
| Atriplex argentea var. expansa | silverscale |
| Atriplex coronata var. coronata | crownscale |
| Atriplex depressa | brittlescale |
| Atriplex fruticulosa | ballscale |
| Atriplex lentiformis | big saltbush |
| Atriplex leucophylla | beach saltbush |
| Atriplex minuscula | lesser saltscale |
| Atriplex prostrata | spearscale |
| Atriplex rosea | tumbling orach |
| Atriplex semibaccata | Australian saltbush |
| Atriplex serenana var. serenana | bractscale |
| Atriplex suberecta | sprawling saltbush |
| Baccharis glutinosa | marsh baccharis |
| Baccharis pilularis subsp. consanguinea | coyote brush |
| Baccharis pilularis subsp. pilularis | |
| Baccharis salicifolia subsp. salicifolia | mule fat, seepwillow |
| Balsamorhiza deltoidea | |
| Balsamorhiza macrolepis | |
| Barbarea orthoceras | winter cress |
| Bassia hyssopifolia | |
| Bellardia trixago var. trixago | |
| Bellis perennis | English daisy |
| Berberis aquifolium var. aquifolium | |
| Berberis aquifolium var. dictyota | |
| Berberis nervosa | Oregon grape |
| Berberis pinnata subsp. pinnata | California barberry |
| Berula erecta | water-parsnip |
| Beta vulgaris subsp. maritima | sea beet |
| Bidens frondosa | sticktight |
| Bidens laevis | bur-marigold |
| Blennosperma nanum var. nanum | |
| Blepharizonia laxa | glandular big tarplant |
| Blepharizonia plumosa | big tarplant |
| Boechera breweri subsp. breweri | Brewer's rock cress |
| Bowlesia incana | |
| Brassica juncea | India mustard |
| Brassica nigra | black mustard |
| Brassica oleracea | cabbage |
| Brassica rapa | field mustard |
| Brickellia californica | California brickelbush |
| Buddleja davidii | butterfly bush |
| Cakile edentula | sea rocket |
| Cakile maritima | sea rocket |
| Calandrinia breweri | |
| Calandrinia menziesii | red maids |
| Calendula arvensis | field-marigold |
| Calendula officinalis | pot-marigold |
| California macrophylla | |
| Callitriche heterophylla var. bolanderi | |
| Callitriche longipedunculata | |
| Callitriche marginata | water-starwort |
| Callitriche trochlearis | |
| Caltha palustris | marsh-marigold |
| Calycadenia multiglandulosa | |
| Calycadenia truncata | rosin weed |
| Calystegia malacophylla subsp. pedicellata | woolly morning-glory |
| Calystegia purpurata subsp. purpurata | |
| Calystegia sepium subsp. limnophila | hedge bindweed |
| Calystegia silvatica subsp. disjuncta | shortstalk false bindweed |
| Calystegia subacaulis subsp. subacaulis | hill morning-glory |
| Camissonia contorta | |
| Camissonia strigulosa | |
| Camissoniopsis cheiranthifolia subsp. cheiranthifolia | dune suncup |
| Camissoniopsis hirtella | |
| Camissoniopsis intermedia | |
| Camissoniopsis micrantha | |
| Campanula exigua | chaparral harebell |
| Campanula griffinii | |
| Capsella bursa-pastoris | shepherd's purse |
| Cardamine californica | milkmaids, tooth wort |
| Cardamine hirsuta | |
| Cardamine oligosperma | |
| Carduus pycnocephalus subsp. pycnocephalus | Italian thistle |
| Carduus tenuiflorus | |
| Carpobrotus chilensis | sea fig |
| Carpobrotus edulis | freeway iceplant |
| Castilleja affinis subsp. affinis | Indian paintbrush |
| Castilleja ambigua subsp. ambigua | johnny-nip |
| Castilleja applegatei subsp. martinii | |
| Castilleja attenuata | valley tassels |
| Castilleja densiflora subsp. densiflora | owl's-clover |
| Castilleja exserta subsp. exserta | purple owl's-clover |
| Castilleja exserta subsp. latifolia | |
| Castilleja foliolosa | woolly paintbrush |
| Castilleja rubicundula subsp. lithospermoides | cream sacs |
| Castilleja subinclusa subsp. franciscana | |
| Castilleja subinclusa subsp. subinclusa | |
| Castilleja wightii | Wight's paintbrush |
| Caulanthus flavescens | |
| Caulanthus lasiophyllus | California mustard |
| Ceanothus cuneatus var. cuneatus | buck brush |
| Ceanothus foliosus | wavy leaved ceanothus |
| Ceanothus leucodermis | chaparral whitethorn |
| Ceanothus oliganthus var. sorediatus | jim brush |
| Ceanothus thyrsiflorus var. thyrsiflorus | |
| Centaurea calcitrapa | purple star-thistle |
| Centaurea cyanus | bachelor's button, cornflower |
| Centaurea iberica | Iberian starthistle |
| Centaurea melitensis | tocalote, Maltese start-thistle |
| Centaurea solstitialis | yellow star-thistle |
| Centranthus ruber | red valerian |
| Centromadia fitchii | Fitch's spikeweed |
| Centromadia parryi subsp. congdonii | Congdon's tarplant |
| Centromadia pungens subsp. pungens | common spikeweed |
| Cephalanthus occidentalis | button bush |
| Cerastium fontanum subsp. vulgare | |
| Cerastium glomeratum | mouse-ear chickweed |
| Cercocarpus betuloides var. betuloides | mountain-mahogany |
| Cestrum parqui | Chilean jessamine |
| Chaenactis glabriuscula var. glabriuscula | yellow pincushion |
| Chaenactis glabriuscula var. heterocarpha | yellow pincushion |
| Chaenactis glabriuscula var. megacephala | |
| Chenopodium album | lamb's quarters |
| Chenopodium berlandieri var. sinuatum | |
| Chenopodium californicum | California pigweed |
| Chenopodium macrospermum | coast goosefoot |
| Chenopodium murale | sowbane |
| Chenopodium pratericola | |
| Chenopodium rubrum | red goosefoot |
| Chenopodium vulvaria | stinking goosefoot |
| Chloropyron molle subsp. hispidum | hispid bird's-beak |
| Chloropyron molle subsp. molle | soft bird's-beak |
| Chloropyron palmatum | palmate bird's-beak |
| Chorizanthe membranacea | pink spineflower |
| Chorizanthe polygonoides var. polygonoides | knotweed spineflower |
| Chrysolepis chrysophylla var. minor | golden chinquapin |
| Cicendia quadrangularis | Oregon timwort |
| Cichorium intybus | chicory |
| Cicuta douglasii | water hemlock |
| Cicuta maculata var. bolanderi | water hemlock |
| Cirsium andrewsii | Franciscan thistle |
| Cirsium brevistylum | Indian thistle |
| Cirsium cymosum var. cymosum | peregrine thistle |
| Cirsium douglasii var. douglasii | swamp thistle |
| Cirsium fontinale var. campylon | Hamilton thistle |
| Cirsium occidentale var. californicum | California thistle |
| Cirsium occidentale var. venustum | venus thistle |
| Cirsium quercetorum | brownie thistle |
| Cirsium remotifolium var. odontolepis | |
| Cirsium vulgare | bull thistle |
| Citrullus lanatus var. citroides | watermelon |
| Clarkia affinis | chaparral clarkia |
| Clarkia biloba subsp. biloba | twolobe clarkia |
| Clarkia breweri | Brewer's clarkia |
| Clarkia concinna subsp. automixa | Santa Clara red ribbons |
| Clarkia concinna subsp. concinna | red ribbons |
| Clarkia epilobioides | |
| Clarkia franciscana | Presidio clarkia |
| Clarkia gracilis subsp. gracilis | slender clarkia |
| Clarkia modesta | |
| Clarkia purpurea subsp. purpurea | purple clarkia |
| Clarkia purpurea subsp. quadrivulnera | four-spot |
| Clarkia purpurea subsp. viminea | four-spot |
| Clarkia rhomboidea | |
| Clarkia rubicunda | farewell-to-spring |
| Clarkia tembloriensis subsp. tembloriensis | temblor range clarkia |
| Clarkia unguiculata | elegant clarkia |
| Claytonia exigua subsp. exigua | little spring beauty |
| Claytonia gypsophiloides | candy stripers |
| Claytonia parviflora subsp. parviflora | |
| Claytonia perfoliata subsp. mexicana | |
| Claytonia perfoliata subsp. perfoliata | Miner's lettuce |
| Clematis lasiantha | pipestems |
| Clematis ligusticifolia | virgin's bower |
| Clinopodium douglasii | yerba buena |
| Collinsia heterophylla var. heterophylla | Chinese houses |
| Collinsia parviflora | blue-eyed mary |
| Collinsia sparsiflora var. collina | |
| Collinsia sparsiflora var. sparsiflora | |
| Collinsia tinctoria | |
| Collomia diversifolia | serpentine collomia |
| Collomia heterophylla | |
| Conium maculatum | poison hemlock |
| Consolida ajacis | |
| Convolvulus arvensis | bindweed |
| Convolvulus simulans | |
| Cordylanthus nidularius | Mt. Diablo bird's-beak |
| Cordylanthus pilosus subsp. pilosus | |
| Cordylanthus rigidus subsp. rigidus | |
| Corethrogyne filaginifolia | |
| Cornus glabrata | brown dogwood |
| Cornus sericea subsp. occidentalis | western dogwood |
| Cornus sericea subsp. sericea | American dogwood |
| Corylus cornuta subsp. californica | California hazelnut |
| Cotoneaster franchetii | |
| Cotoneaster lacteus | |
| Cotoneaster pannosus | |
| Cotula australis | |
| Cotula coronopifolia | brass-buttons |
| Crassula aquatica | water pygmy-weed |
| Crassula connata | pygmy-weed |
| Crassula tillaea | |
| Crataegus monogyna | hawthorn |
| Crepis bursifolia | |
| Crepis capillaris | |
| Crepis monticola | |
| Crepis vesicaria subsp. taraxacifolia | |
| Cressa truxillensis | alkali weed |
| Crocanthemum scoparium var. vulgare | peak rush-rose |
| Crocidium multicaule | spring gold |
| Croton californicus | |
| Croton setiger | turkey mullein |
| Cryptantha clevelandii var. florosa | |
| Cryptantha corollata | |
| Cryptantha flaccida | |
| Cryptantha intermedia var. intermedia | |
| Cryptantha juniperensis | rigid cryptantha |
| Cryptantha micromeres | |
| Cryptantha microstachys | |
| Cryptantha torreyana var. pumila | dwarf cryptantha |
| Cucurbita foetidissima | calabazilla |
| Cuscuta californica var. californica | |
| Cuscuta campestris | field dodder |
| Cuscuta japonica var. formosana | Japanese dodder |
| Cuscuta pacifica var. pacifica | |
| Cuscuta salina | |
| Cuscuta subinclusa | canyon dodder |
| Cyclospermum leptophyllum | marsh-parsley |
| Cymbalaria muralis | Kenilworth-ivy |
| Cynara cardunculus | artichoke thistle, cardoon |
| Cypselea humifusa | |
| Cytisus scoparius | Scotch broom |
| Cytisus striatus | |
| Datisca glomerata | durango root |
| Datura stramonium | jimson weed |
| Datura wrightii | |
| Daucus carota | Queen Anne's lace |
| Daucus pusillus | |
| Deinandra bacigalupii | Livermore moonshine |
| Deinandra corymbosa | |
| Deinandra kelloggii | |
| Deinandra lobbii | |
| Delairea odorata | German-ivy |
| Delphinium californicum subsp. californicum | |
| Delphinium californicum subsp. interius | California larkspur |
| Delphinium decorum subsp. decorum | coast larkspur |
| Delphinium gypsophilum | gypsum-loving larkspur |
| Delphinium hansenii subsp. hansenii | Hansen's larkspur |
| Delphinium hesperium subsp. hesperium | western larkspur |
| Delphinium hesperium subsp. pallescens | |
| Delphinium nudicaule | red larkspur |
| Delphinium parryi subsp. parryi | Parry's larkspur |
| Delphinium patens subsp. patens | spreading larkspur |
| Delphinium variegatum subsp. variegatum | royal larkspur |
| Dendromecon rigida | bush poppy |
| Dianthus nudiflorus | |
| Dicentra formosa | bleeding heart |
| Dichondra donelliana | California ponysfoot |
| Dichondra micrantha | |
| Digitalis purpurea | foxglove |
| Diplacus aurantiacus | bush monkeyflower |
| Diplacus bolanderi | |
| Diplacus douglasii | Douglas monkeyflower |
| Diplacus rattanii | Rattan monkeyflower |
| Dipsacus sativus | teasel |
| Dirca occidentalis | western leatherwood |
| Dittrichia graveolens | stinkwort |
| Downingia cuspidata | |
| Downingia insignis | |
| Downingia pulchella | |
| Draba cuneifolia | |
| Draba verna | spring whitlow-grass |
| Drymocallis glandulosa var. wrangelliana | sticky cinquefoil |
| Duchesnea indica var. indica | mock-strawberry |
| Dudleya cymosa subsp. cymosa | |
| Dudleya cymosa subsp. paniculata | |
| Dudleya farinosa | |
| Dysphania ambrosioides | Mexican tea |
| Dysphania botrys | Jerusaleum-oak |
| Dysphania multifida | cut leaf pigweed |
| Echium candicans | Pride of Madeira |
| Eclipta prostrata | |
| Ehrendorferia chrysantha | golden ear-drops |
| Elatine brachysperma | waterwort |
| Elatine californica | waterwort |
| Emmenanthe penduliflora | whispering bells |
| Enemion occidentale | |
| Enemion stipitatum | |
| Epilobium brachycarpum | |
| Epilobium campestre | |
| Epilobium canum subsp. canum | California fuschia |
| Epilobium ciliatum subsp. ciliatum | willow-herb |
| Epilobium ciliatum subsp. watsonii | |
| Epilobium cleistogamum | |
| Epilobium densiflorum | |
| Epilobium minutum | |
| Epilobium torreyi | |
| Eremalche exilis | |
| Eremalche parryi subsp. parryi | |
| Eremothera boothii subsp. decorticans | shredding evening-primrose |
| Eriastrum abramsii | |
| Eriastrum ertterae | Lime Ridge eriastrum |
| Eriastrum pluriflorum subsp. pluriflorum | |
| Ericameria arborescens | golden-fleece |
| Ericameria linearifolia | interior goldenbush |
| Ericameria nauseosa var. mohavensis | rabbitbrush |
| Erigeron bonariensis | |
| Erigeron canadensis | horseweed |
| Erigeron foliosus var. franciscensis | |
| Erigeron petrophilus var. petrophilus | |
| Erigeron philadelphicus var. philadelphicus | |
| Erigeron reductus var. angustatus | |
| Erigeron sumatrensis | |
| Eriobotrya japonica | loquat |
| Eriodictyon californicum | yerba santa |
| Eriogonum angulosum | |
| Eriogonum covilleanum | |
| Eriogonum fasciculatum var. foliolosum | California buckwheat |
| Eriogonum fasciculatum var. polifolium | |
| Eriogonum gracile var. gracile | slender buckwheat |
| Eriogonum inerme var. inerme | unarmed buckwheat |
| Eriogonum luteolum var. caninum | Tiburon buckwheat |
| Eriogonum luteolum var. luteolum | |
| Eriogonum nudum var. auriculatum | eared buckwheat |
| Eriogonum nudum var. pauciflorum | |
| Eriogonum nudum var. psychicola | Antioch Dunes buckwheat |
| Eriogonum roseum | virgate buckwheat |
| Eriogonum truncatum | Mt. Diablo buckwheat |
| Eriogonum umbellatum var. bahiiforme | sulfur flower |
| Eriogonum wrightii var. trachygonum | |
| Eriophyllum confertiflorum var. confertiflorum | golden-yarrow |
| Eriophyllum jepsonii | Jepson's woolly-sunflower |
| Eriophyllum lanatum var. achilleoides | |
| Eriophyllum staechadifolium | seaside woolly-sunflower |
| Erodium botrys | long-beaked filaree |
| Erodium brachycarpum | |
| Erodium cicutarium | red-stemmed filaree |
| Erodium malacoides | |
| Erodium moschatum | white-stem filaree |
| Eryngium aristulatum var. aristulatum | coyote-thistle |
| Eryngium aristulatum var. hooveri | |
| Eryngium aristulatum | Jepson's button celery |
| Eryngium armatum | |
| Eryngium articulatum | |
| Eryngium castrense | |
| Eryngium jepsonii | |
| Eryngium spinosepalum | |
| Eryngium vaseyi var. vallicola | |
| Erysimum capitatum var. angustatum | Contra Costa wallflower |
| Erysimum capitatum var. capitatum | western wallflower |
| Erythranthe arvensis | villous-bracted monkeyflower, field monkeyflower |
| Erythranthe cardinalis | scarlet monkeyflower |
| Erythranthe guttata | seep monkeyflower |
| Erythranthe inconspicua | small-flowered monkeyflower |
| Erythranthe latidens | broad-tooth monkeyflower |
| Erythranthe microphylla | small leaved monkeyflower |
| Erythranthe nasuta | shy monkeyflower |
| Eschscholzia caespitosa | tufted poppy |
| Eschscholzia californica | California poppy |
| Eschscholzia rhombipetala | |
| Eucalyptus camaldulensis | red gum |
| Eucalyptus globulus | blue gum |
| Eucalyptus pulchella | |
| Eucalyptus sideroxylon | red ironbark |
| Eucalyptus tereticornis | red forest gum |
| Eucalyptus viminalis | manna gum |
| Eucrypta chrysanthemifolia var. chrysanthemifolia | |
| Euonymus occidentalis var. occidentalis | burning bush |
| Euphorbia crenulata | |
| Euphorbia lathyris | caper spurge |
| Euphorbia maculata | spotted spurge |
| Euphorbia oblongata | golden spurge |
| Euphorbia ocellata subsp. ocellata | Contura Creek sandmat |
| Euphorbia peplus | petty spurge |
| Euphorbia serpens | creeping spurge |
| Euphorbia serpillifolia subsp. serpillifolia | thyme-leafed spurge |
| Euphorbia spathulata | spatulate spurge |
| Eurybia radulina | broad-leaf aster |
| Euthamia occidentalis | western goldenrod |
| Extriplex joaquinana | San Joaquin saltbush |
| Fallopia japonica | Japanese knotweed |
| Ficus carica | fig |
| Foeniculum vulgare | fennel |
| Forestiera pubescens | desert olive |
| Fragaria vesca | wood strawberry |
| Frangula californica subsp. californica | California coffeeberry |
| Frangula californica subsp. tomentella | hoary coffeeberry |
| Frankenia salina | alkali heath |
| Fraxinus dipetala | flowering ash |
| Fraxinus latifolia | Oregon ash |
| Fremontodendron californicum | flannelbush |
| Fumaria capreolata | white ramping fumitory |
| Fumaria officinalis | fumitory |
| Galium andrewsii subsp. gatense | needle bedstraw |
| Galium aparine | bedstraw, cleavers |
| Galium californicum subsp. californicum | California bedstraw |
| Galium divaricatum | Lamarck's bedstraw |
| Galium murale | tiny bedstraw |
| Galium parisiense | wall bedstraw |
| Galium porrigens var. porrigens | climbing bedstraw |
| Galium porrigens var. tenue | |
| Galium tricornutum | rough corn bedstraw |
| Galium trifidum subsp. columbianum | |
| Galium triflorum | sweet-scented bedstraw |
| Gamochaeta pensylvanica | |
| Gamochaeta ustulata | featherweed |
| Garrya elliptica | wavy-leaf silk tassel bush |
| Garrya flavescens | ashy silk tassel |
| Gaultheria shallon | salal |
| Genista monspessulana | French broom |
| Geranium carolinianum | Carolina geranium |
| Geranium core-core | |
| Geranium dissectum | cut-leaved geranium |
| Geranium lucidum | |
| Geranium molle | cranes-bill geranium |
| Geranium potentilloides | |
| Geranium purpureum | little robin |
| Geranium robertianum | |
| Geranium rotundifolium | |
| Gilia achilleifolia subsp. achilleifolia | |
| Gilia achilleifolia subsp. multicaulis | |
| Gilia capitata subsp. capitata | |
| Gilia capitata subsp. staminea | |
| Gilia clivorum | purplespot gilia |
| Gilia tricolor subsp. diffusa | bird's-eye gilia |
| Gilia tricolor subsp. tricolor | bird's-eye gilia |
| Githopsis diffusa subsp. robusta | |
| Githopsis specularioides | bluecup |
| Glebionis segetum | corn chrysanthemum |
| Glinus lotoides | |
| Glycyrrhiza lepidota | wild licorice |
| Gnaphalium palustre | lowland cudweed |
| Gratiola ebracteata | bractless hedge hyssop |
| Grindelia camporum | |
| Grindelia hirsutula | |
| Grindelia stricta var. angustifolia | marsh gumplant |
| Gruvelia pusilla | little combseed |
| Gutierrezia californica | California matchweed |
| Hedera canariensis | Canary Islands ivy |
| Hedera helix | English ivy |
| Hedypnois rhagadioloides | |
| Helenium bigelovii | |
| Helenium puberulum | sneezeweed |
| Helianthella californica var. californica | helianthella |
| Helianthella castanea | Diablo helianthella |
| Helianthus annuus | sunflower |
| Helianthus californicus | California sunflower |
| Helianthus gracilentus | |
| Heliotropium curassavicum var. oculatum | heliotrope |
| Helminthotheca echioides | bristly ox-tongue |
| Hemizonia congesta subsp. lutescens | |
| Hemizonia congesta subsp. luzulifolia | |
| Heracleum maximum | cow parsnip |
| Herniaria hirsuta var. cinerea | rupturewort |
| Hesperevax caulescens | hogwallow starfish |
| Hesperevax sparsiflora var. sparsiflora | |
| Hesperocnide tenella | black haired nettle |
| Hesperolinon breweri | Brewer's dwarf flax |
| Hesperolinon californicum | California dwarf flax |
| Hesperolinon clevelandii | |
| Hesperolinon disjunctum | |
| Hesperolinon micranthum | |
| Heterocodon rariflorum | |
| Heteromeles arbutifolia | toyon |
| Heterotheca grandiflora | telegraph weed |
| Heterotheca oregona var. rudis | Oregon goldenaster |
| Heterotheca oregona var. scaberrima | goldenaster |
| Heterotheca sessiliflora subsp. bolanderi | Bolander's goldenaster |
| Heterotheca sessiliflora subsp. echioides | |
| Heuchera micrantha | alumroot |
| Hibiscus lasiocarpos var. occidentalis | rose-mallow |
| Hieracium albiflorum | white hawkweed |
| Hirschfeldia incana | hoary mustard |
| Hoita macrostachya | |
| Holocarpha heermannii | Heermann's tarweed |
| Holocarpha macradenia | Santa Cruz tarplant |
| Holocarpha obconica | |
| Holocarpha virgata subsp. virgata | |
| Holodiscus discolor var. discolor | cream bush, oceanspray |
| Holozonia filipes | Greene's white crown |
| Horkelia californica var. californica | California horkelia |
| Horkelia californica var. elata | tall horkelia |
| Horkelia californica var. frondosa | leafy horkelia |
| Hornungia procumbens | |
| Hosackia crassifolia var. crassifolia | |
| Hosackia stipularis var. stipularis | |
| Hydrocotyle ranunculoides | |
| Hydrocotyle verticillata | |
| Hydrophyllum occidentale | western waterleaf |
| Hypericum androsaemum | |
| Hypericum perforatum subsp. perforatum | Klamath weed |
| Hypochaeris glabra | smooth cat's ear |
| Hypochaeris radicata | rough cat's ear |
| Idahoa scapigera | flat-pod |
| Ilex aquifolium | English holly |
| Impatiens balfourii | touch-me-not |
| Iva axillaris | poverty weed |
| Jaumea carnosa | |
| Juglans californica | Southern California black walnut |
| Keckiella breviflora var. breviflora | |
| Keckiella corymbosa | |
| Kickxia elatine | fluellin |
| Kickxia spuria | fluellin |
| Kopsiopsis strobilacea | California ground-cone |
| Lactuca saligna | |
| Lactuca serriola | prickly lettuce |
| Lactuca virosa | |
| Laennecia coulteri | |
| Lagophylla ramosissima | hare's-ear |
| Lamium amplexicaule | henbit |
| Lapsana communis | |
| Lastarriaea coriacea | |
| Lasthenia californica subsp. californica | goldfields |
| Lasthenia conjugens | Contra Costa goldfields |
| Lasthenia ferrisiae | |
| Lasthenia fremontii | goldfields |
| Lasthenia glaberrima | goldfields |
| Lasthenia glabrata subsp. glabrata | |
| Lasthenia gracilis | |
| Lasthenia microglossa | |
| Lasthenia minor | |
| Lasthenia platycarpha | |
| Lathyrus jepsonii var. californicus | |
| Lathyrus jepsonii var. jepsonii | delta tule pea |
| Lathyrus latifolius | perennial sweet-pea |
| Lathyrus vestitus var. vestitus | Pacific pea |
| Layia chrysanthemoides | |
| Layia gaillardioides | woodland tidy-tips |
| Layia hieracioides | tall tidy-tips |
| Layia platyglossa | tidy-tips |
| Legenere limosa | false Venus' looking glass |
| Lepechinia calycina | pitcher sage |
| Lepidium acutidens | |
| Lepidium appelianum | white-top |
| Lepidium chalepense | lens podded hoary cress |
| Lepidium coronopus | swine cress |
| Lepidium dictyotum | |
| Lepidium didymum | wart cress |
| Lepidium draba | hoary cress |
| Lepidium latifolium | perennial pepperweed |
| Lepidium latipes | dwarf peppergrass |
| Lepidium nitidum | shining peppergrass |
| Lepidium oxycarpum | |
| Lepidium pinnatifidum | |
| Lepidium strictum | |
| Leptosiphon ambiguus | serpentine linanthus |
| Leptosiphon androsaceus | |
| Leptosiphon aureus | |
| Leptosiphon bicolor | bicolored linanthus |
| Leptosiphon bolanderi | |
| Leptosiphon ciliatus | whisker brush |
| Leptosiphon liniflorus | |
| Leptosiphon parviflorus | |
| Leptosiphon pygmaeus subsp. continentalis | |
| Leptosyne calliopsidea | |
| Leptosyne hamiltonii | Mt. Hamilton coreopsis |
| Lessingia nemaclada | |
| Lessingia pectinata var. tenuipes | |
| Lessingia ramulosa | |
| Lessingia tenuis | spring lessingia |
| Lewisia rediviva var. rediviva | bitterroot |
| Ligusticum apiifolium | |
| Ligustrum lucidum | Chinese privet |
| Lilaeopsis masonii | Mason's lilaeopsis |
| Limnanthes douglasii subsp. douglasii | meadowfoam |
| Limonium californicum | sea-lavender |
| Limonium ramosissimum | Algerian sea-lavender |
| Limosella acaulis | |
| Limosella australis | delta mudwort |
| Linanthus dichotomus subsp. dichotomus | evening snow |
| Linanthus dichotomus subsp. meridianus | |
| Linum bienne | |
| Lithophragma affine | woodland star |
| Lithophragma bolanderi | |
| Lithophragma heterophyllum | hill starflower |
| Lithophragma parviflorum var. parviflorum | |
| Lobularia maritima | sweet alyssum |
| Logfia filaginoides | herba impia |
| Logfia gallica | |
| Lomatium californicum | chu-chu-pate |
| Lomatium caruifolium var. caruifolium | |
| Lomatium caruifolium var. denticulatum | |
| Lomatium dasycarpum subsp. dasycarpum | |
| Lomatium macrocarpum | |
| Lomatium nudicaule | |
| Lomatium utriculatum | |
| Lonicera hispidula | California honeysuckle |
| Lonicera interrupta | chaparral honeysuckle |
| Lonicera involucrata var. ledebourii | black twinberry |
| Lonicera japonica | Japanese honeysuckle |
| Lonicera subspicata var. denudata | moronel |
| Lotus corniculatus | birdfoot trefoil |
| Ludwigia hexapetala | Uruguayan primrose-willow |
| Ludwigia peploides subsp. montevidensis | water-primrose |
| Ludwigia peploides subsp. peploides | |
| Lunaria annua | moonwort |
| Lupinus affinis | |
| Lupinus albifrons var. albifrons | bush lupine |
| Lupinus albifrons var. collinus | |
| Lupinus arboreus | yellow bush lupine |
| Lupinus bicolor | miniature lupine |
| Lupinus concinnus | Bajada lupine |
| Lupinus formosus var. formosus | summer lupine, western lupine |
| Lupinus latifolius var. latifolius | broadleaf lupine, wood lupine |
| Lupinus microcarpus var. densiflorus | |
| Lupinus microcarpus var. microcarpus | chick lupine |
| Lupinus nanus | sky lupine |
| Lupinus pachylobus | big pod lupine |
| Lupinus succulentus | arroyo lupine |
| Lychnis coronaria | rose campion |
| Lycopus americanus | cutleaf bugleweed |
| Lycopus asper | bugleweed |
| Lysimachia arvensis | scarlet pimpernel |
| Lysimachia latifolia | starflower |
| Lysimachia maritima | sea-milkwort |
| Lysimachia minima | chaffweed |
| Lysimachia monelli | flaxleaf pimpernel |
| Lythrum californicum | California loosestrife |
| Lythrum hyssopifolia | grass-poly |
| Lythrum salicaria | |
| Lythrum tribracteatum | |
| Madia elegans | common madia |
| Madia exigua | threadstem madia |
| Madia gracilis | slender tarweed |
| Madia sativa | coast tarweed |
| Malacothamnus arcuatus var. elmeri | |
| Malacothamnus fremontii var. fremontii | long-haired unfurled bushmallow |
| Malacothrix clevelandii | Cleveland's malacothrix |
| Malacothrix coulteri | snake's-head |
| Malacothrix floccifera | |
| Malva assurgentiflora | island mallow |
| Malva multiflora | Cretan mallow |
| Malva nicaeensis | bull mallow |
| Malva parviflora | cheeseweed |
| Malvella leprosa | alkali-mallow |
| Marah fabacea | California man-root |
| Marah oregana | coast man-root |
| Marrubium vulgare | horehound |
| Matricaria discoidea | pineapple weed |
| Maytenus boaria | mayten |
| Meconella californica | |
| Meconella oregana | |
| Medicago arabica | spotted burclover |
| Medicago lupulina | black medick |
| Medicago polymorpha | burclover |
| Medicago sativa | alfalfa |
| Melilotus albus | white sweetclover |
| Melilotus indicus | sourclover |
| Melissa officinalis | lemon balm |
| Mentha ×gracilis | Scotch spearmint |
| Mentha ×piperita | peppermint |
| Mentha aquatica | water mint |
| Mentha arvensis | field mint |
| Mentha canadensis | American cornmint |
| Mentha pulegium | pennyroyal |
| Mentha spicata | spearmint |
| Mentha suaveolens | pineapple mint |
| Mentzelia affinis | |
| Mentzelia dispersa | |
| Mentzelia lindleyi | |
| Mentzelia micrantha | |
| Mercurialis annua | annual mercury |
| Mesembryanthemum nodiflorum | |
| Micranthes californica | |
| Micropus californicus var. californicus | slender cottonweed |
| Micropus californicus var. subvestitus | |
| Microseris acuminata | |
| Microseris campestris | |
| Microseris douglasii subsp. douglasii | silver puffs |
| Microseris douglasii subsp. tenella | |
| Microseris elegans | |
| Microseris sylvatica | |
| Microsteris gracilis | |
| Mimetanthe pilosa | |
| Mirabilis laevis var. crassifolia | California four o'clock |
| Modiola caroliniana | |
| Moehringia macrophylla | large-leaved sandwort |
| Mollugo verticillata | |
| Monardella douglasii | |
| Monardella villosa subsp. villosa | coyote-mint |
| Monolepis nuttalliana | poverty weed |
| Monolopia gracilens | |
| Monolopia lanceolata | |
| Monolopia major | |
| Montia fontana | water chickweed |
| Morella californica | wax myrtle |
| Muehlenbeckia complexa | maidenhair vine |
| Myoporum laetum | |
| Myosotis discolor | |
| Myosotis latifolia | forget-me-not |
| Myosotis laxa | |
| Myosurus minimus subsp. apus | little mousetail |
| Myosurus minimus | mouse-tail |
| Myosurus sessilis | |
| Myriophyllum aquaticum | parrot's feather |
| Myriophyllum sibiricum | |
| Myriophyllum spicatum | Eurasian milfoil |
| Myriophyllum verticillatum | |
| Nasturtium officinale | water cress |
| Navarretia atractyloides | holly-leaf navarretia |
| Navarretia cotulifolia | cotula navarretia |
| Navarretia gowenii | Gowen's navarretia |
| Navarretia hamata subsp. parviloba | hooked navarretia |
| Navarretia heterandra | Tehama navarretia |
| Navarretia intertexta | needleleaf navarretia |
| Navarretia mellita | |
| Navarretia nigelliformis subsp. radians | adobe navarretia |
| Navarretia prostrata | |
| Navarretia pubescens | downy pincushion |
| Navarretia squarrosa | skunkweed |
| Navarretia viscidula | sticky navarretia |
| Nemophila heterophylla | |
| Nemophila menziesii var. menziesii | baby blue-eyes |
| Nemophila parviflora var. parviflora | |
| Nemophila pedunculata | |
| Nicotiana acuminata var. multiflora | |
| Nicotiana attenuata | |
| Nicotiana glauca | tree tobacco |
| Nicotiana quadrivalvis | Indian tobacco |
| Nitrophila occidentalis | borax weed |
| Nuttallanthus texanus | blue toadflax |
| Oemleria cerasiformis | oso berrry |
| Oenanthe sarmentosa | |
| Oenothera biennis | common evening-primrose |
| Oenothera deltoides subsp. cognata | |
| Oenothera deltoides subsp. howellii | Antioch Dunes evening-primrose |
| Oenothera elata subsp. hookeri | evening primrose |
| Oenothera glazioviana | |
| Oenothera laciniata | |
| Oenothera sinuosa | wavyleaf gaura |
| Oenothera xenogaura | |
| Olea europaea | olive |
| Osmorhiza berteroi | wood cicely |
| Osmorhiza brachypoda | California cicely |
| Oxalis corniculata | creeping wood sorrel |
| Oxalis incarnata | crimson wood sorrel |
| Oxalis oregana | redwood sorrel |
| Oxalis pes-caprae | Bermuda-buttercup |
| Oxalis pilosa | hairy wood sorrel |
| Packera breweri | Brewer groundsel |
| Papaver californicum | fire poppy |
| Papaver heterophyllum | wind poppy |
| Parietaria hespera var. californica | California pellitory |
| Parietaria judaica | |
| Passiflora tarminiana | banana passion vine |
| Pectocarya penicillata | sleeping combseed |
| Pedicularis densiflora | warrior's plume |
| Pediomelum californicum | Indian breadroot |
| Pelargonium grossularioides | |
| Pelargonium inquinans | geranium |
| Penstemon centranthifolius | scarlet bugler |
| Penstemon heterophyllus var. heterophyllus | chaparral penstemon |
| Penstemon heterophyllus var. purdyi | foothill penstemon |
| Pentachaeta alsinoides | tiny pygmy daisy |
| Pentachaeta exilis subsp. exilis | meager pygmy daisy |
| Perideridia californica | California yampah |
| Perideridia kelloggii | Kellog's yampah |
| Perideridia oregana | Oregon yampah |
| Persicaria amphibia | water smartweed |
| Persicaria hydropiper | waterpepper |
| Persicaria hydropiperoides | false waterpepper |
| Persicaria lapathifolia | willow weed |
| Persicaria maculosa | lady's thumb |
| Persicaria punctata | |
| Petasites frigidus var. palmatus | coltsfoot |
| Petrorhagia dubia | pink grass |
| Petunia parviflora | wild petunia |
| Phacelia breweri | |
| Phacelia californica | rock phacelia |
| Phacelia ciliata | great valley phacelia |
| Phacelia distans | sordid phacelia, distant phacelia |
| Phacelia divaricata | |
| Phacelia douglasii | |
| Phacelia imbricata var. imbricata | mountain phacelia |
| Phacelia malvifolia var. malvifolia | |
| Phacelia nemoralis var. nemoralis | bristly phacelia |
| Phacelia phacelioides | Mt. Diablo phacelia |
| Phacelia ramosissima | branching phacelia |
| Phacelia rattanii | |
| Phacelia suaveolens | sweet scented phacelia |
| Phacelia tanacetifolia | tansy-leaf phacelia |
| Phelipanche ramosa | |
| Pholistoma auritum var. auritum | fiesta flower |
| Pholistoma membranaceum | white fiesta flower |
| Phoradendron leucarpum subsp. macrophyllum | big leaf mistletoe |
| Phoradendron leucarpum subsp. tomentosum | oak mistletoe |
| Phyla nodiflora | |
| Physocarpus capitatus | ninebark |
| Phytolacca heterotepala | Mexican pokeweed |
| Pickeringia montana var. montana | chaparral pea |
| Pistacia atlantica | |
| Pittosporum crassifolium | |
| Plagiobothrys acanthocarpus | adobe allocarya |
| Plagiobothrys arizonicus | |
| Plagiobothrys bracteatus | |
| Plagiobothrys canescens var. canescens | |
| Plagiobothrys fulvus var. campestris | |
| Plagiobothrys glaber | hairless popcornflower |
| Plagiobothrys greenei | |
| Plagiobothrys humistratus | |
| Plagiobothrys leptocladus | alkali plagiobothrys |
| Plagiobothrys nothofulvus | popcornflower |
| Plagiobothrys stipitatus var. micranthus | |
| Plagiobothrys stipitatus var. stipitatus | |
| Plagiobothrys tenellus | |
| Plagiobothrys trachycarpus | |
| Plagiobothrys undulatus | |
| Plantago coronopus | cutleaf plantain |
| Plantago elongata | coastal plantain |
| Plantago erecta | California plantain |
| Plantago lanceolata | English plantain |
| Plantago major | common plantain |
| Plantago subnuda | naked plantain |
| Platanus racemosa | western sycamore |
| Platystemon californicus | cream cups |
| Plectritis ciliosa | |
| Plectritis congesta subsp. brachystemon | |
| Plectritis macrocera | |
| Pluchea odorata var. odorata | saltmarsh fleabane |
| Pogogyne serpylloides | |
| Pogogyne zizyphoroides | |
| Polycarpon tetraphyllum subsp. tetraphyllum | four-leaved allseed |
| Polygonum argyrocoleon | persian knotweed |
| Polygonum aviculare subsp. aviculare | |
| Polygonum aviculare subsp. depressum | |
| Polygonum aviculare subsp. neglectum | |
| Polygonum aviculare subsp. rurivagum | |
| Polygonum ramosissimum subsp. ramosissimum | bushy knotweed |
| Populus fremontii subsp. fremontii | Fremont cottonwood |
| Populus trichocarpa | black cottonwood |
| Portulaca oleracea | common purslane |
| Potentilla anserina subsp. pacifica | |
| Potentilla rivalis | river cinquefoil |
| Poterium sanguisorba | burnet |
| Primula clevelandii var. patula | shooting star |
| Primula hendersonii | shooting star |
| Proboscidea lutea | devil's claw |
| Prunella vulgaris var. lanceolata | |
| Prunella vulgaris var. vulgaris | |
| Prunus cerasifera | cherry plum |
| Prunus dulcis | almond |
| Prunus emarginata | bitter cherry |
| Prunus ilicifolia subsp. ilicifolia | |
| Prunus subcordata | |
| Prunus virginiana var. demissa | western choke-cherry |
| Pseudognaphalium beneolens | |
| Pseudognaphalium biolettii | |
| Pseudognaphalium californicum | |
| Pseudognaphalium luteoalbum | cudweed |
| Pseudognaphalium microcephalum | |
| Pseudognaphalium ramosissimum | |
| Pseudognaphalium stramineum | |
| Pseudognaphalium thermale | |
| Psilocarphus brevissimus var. brevissimus | dwarf woolly-marbles |
| Psilocarphus chilensis | round woolly-marbles |
| Psilocarphus oregonus | Oregon woolly-marbles |
| Psilocarphus tenellus | slender woolly-marbles |
| Ptelea crenulata | hop tree |
| Pterostegia drymarioides | |
| Pyracantha angustifolia | slender firethorn |
| Pyracantha coccinea | |
| Pyracantha crenulata | |
| Pyracantha fortuneana | Chinese firethorn |
| Quercus agrifolia | |
| Quercus berberidifolia | scrub oak |
| Quercus chrysolepis | canyon live oak |
| Quercus douglasii | blue oak |
| Quercus durata var. durata | leather oak |
| Quercus garryana var. garryana | Oregon oak |
| Quercus ilex | holly oak |
| Quercus kelloggii | California black oak |
| Quercus lobata | valley oak |
| Quercus palmeri | Palmer's oak |
| Quercus parvula var. shrevei | |
| Quercus wislizeni var. frutescens | |
| Quercus wislizeni var. wislizeni | interior live oak |
| Rafinesquia californica | California chicory |
| Ranunculus aquatilis var. aquatilis | |
| Ranunculus aquatilis var. diffusus | water buttercup |
| Ranunculus californicus | California buttercup |
| Ranunculus canus var. canus | |
| Ranunculus hebecarpus | pubescent-fruited buttercup |
| Ranunculus lobbii | Lobb's buttercup |
| Ranunculus muricatus | spiny buttercup |
| Ranunculus occidentalis var. occidentalis | |
| Ranunculus repens | |
| Ranunculus sceleratus | cursed crowsfoot |
| Raphanus raphanistrum | jointed charlock |
| Raphanus sativus | wild radish |
| Rhamnus alaternus | Italian buckthorn |
| Rhamnus crocea | spiny redberry |
| Rhamnus ilicifolia | holly-leaf redberry |
| Rhaponticum repens | Russian knapweed |
| Rhinotropis californica | California milkwort |
| Rhus aromatica | skunkbrush |
| Ribes aureum var. gracillimum | golden currant |
| Ribes californicum var. californicum | hillside gooseberry |
| Ribes divaricatum var. pubiflorum | straggly gooseberry |
| Ribes malvaceum var. malvaceum | pink-flowering currant |
| Ribes menziesii | canyon gooseberry |
| Ribes quercetorum | oak gooseberry |
| Ribes sanguineum var. glutinosum | red-flowering currant |
| Ribes speciosum | fuchsia-flowered gooseberry |
| Ricinus communis | castor-bean |
| Rigiopappus leptocladus | |
| Robinia pseudoacacia | black locust |
| Romanzoffia californica | |
| Rorippa curvisiliqua | yellow cress |
| Rorippa palustris subsp. palustris | |
| Rosa californica | California rose |
| Rosa gymnocarpa | wood rose |
| Rosa rubiginosa | sweet-brier |
| Rosa spithamea | ground rose |
| Rubus armeniacus | Himalayan blackberry |
| Rubus laciniatus | cutleaf blackberry |
| Rubus parviflorus | thimbleberry |
| Rubus pensilvanicus | |
| Rubus ulmifolius var. anoplothyrsus | |
| Rubus ursinus | California blackberry |
| Rumex acetosella | sheep sorrel |
| Rumex californicus | |
| Rumex conglomeratus | green dock |
| Rumex crassus | |
| Rumex crispus | curly dock |
| Rumex fueginus | golden dock |
| Rumex obtusifolius | bitter dock |
| Rumex occidentalis | western dock |
| Rumex pulcher | fiddle dock |
| Rumex salicifolius | willow dock |
| Rumex transitorius | |
| Rupertia physodes | California tea |
| Sabulina californica | California sandwort |
| Sabulina douglasii | Douglas sandwort |
| Sabulina pusilla | least sandwort |
| Sagina apetala | dwarf pearlwort |
| Sagina decumbens subsp. occidentalis | western pearlwort |
| Sagina procumbens | matted pearlwort |
| Salicornia depressa | glasswort |
| Salicornia pacifica | pickleweed |
| Salicornia rubra | |
| Salix exigua var. hindsiana | Hind's willow |
| Salix gooddingii | Goodding's black willow |
| Salix laevigata | red willow |
| Salix lasiandra var. lasiandra | Pacific willow |
| Salix lasiolepis | arroyo willow |
| Salix scouleriana | Scouler's willow |
| Salix sitchensis | Sitka willow |
| Salpichroa origanifolia | |
| Salsola australis | |
| Salsola soda | |
| Salsola tragus | Russian thistle |
| Salvia apiana | |
| Salvia columbariae | chia |
| Salvia leucophylla | |
| Salvia mellifera | black sage |
| Salvia spathacea | |
| Sambucus mexicana | blue elderberry |
| Sambucus racemosa var. racemosa | red elderberry |
| Samolus parviflorus | water-pimpernel |
| Sanicula bipinnata | poison sanicle |
| Sanicula bipinnatifida | purple sanicle |
| Sanicula crassicaulis | Pacific sanicle |
| Sanicula laciniata | |
| Sanicula saxatilis | rock sanicle |
| Sanicula tuberosa | |
| Scabiosa atropurpurea | pincushion flower |
| Scandix pecten-veneris | Venus' needle |
| Schinus molle | peruvian pepper-tree |
| Scolymus hispanicus | golden thistle |
| Scrophularia californica | California figwort |
| Scutellaria californica | |
| Scutellaria siphocampyloides | |
| Scutellaria tuberosa | |
| Sedella pentandra | |
| Sedum radiatum subsp. radiatum | |
| Sedum spathulifolium | broadleaf stonecrop |
| Senecio aronicoides | rayless ragwort |
| Senecio flaccidus var. douglasii | Douglas' ragwort |
| Senecio glomeratus | cutleaf burnweed |
| Senecio hydrophilus | water ragwort |
| Senecio jacobaea | tansy ragwort |
| Senecio minimus | Australian fireweed |
| Senecio sylvaticus | woodland ragwort |
| Senecio vulgaris | common groundsel |
| Sesuvium verrucosum | sea-purslane |
| Sherardia arvensis | field madder |
| Sidalcea diploscypha | fringed checkerbloom |
| Sidalcea malviflora subsp. laciniata | checker mallow |
| Sidalcea malviflora subsp. malviflora | checker mallow |
| Silene antirrhina | sleepy catchfly |
| Silene gallica | windmill pink |
| Silene laciniata subsp. californica | |
| Silene lemmonii | Lemmon's catchfly |
| Silene verecunda | |
| Silybum marianum | milk-thistle |
| Sinapis arvensis | charlock |
| Sisymbrium irio | London rocket |
| Sisymbrium officinale | hedge mustard |
| Sisymbrium orientale | |
| Sium suave | |
| Solanum americanum | |
| Solanum elaeagnifolium | white horse-nettle |
| Solanum furcatum | |
| Solanum lanceolatum | lanceleaf nightshade |
| Solanum nigrum | black nightshade |
| Solanum physalifolium var. nitidibaccatum | nightshade |
| Solanum umbelliferum | blue witch |
| Soleirolia soleirolii | baby's tears |
| Solidago elongata | Canada goldenrod |
| Solidago velutina subsp. californica | California goldenrod |
| Soliva sessilis | |
| Sonchus asper subsp. asper | prickly sow-thistle |
| Sonchus oleraceus | common sow-thistle |
| Sonchus tenerrimus | |
| Spartium junceum | Spanish broom |
| Spergula arvensis | spurrey |
| Spergularia bocconi | |
| Spergularia macrotheca var. leucantha | |
| Spergularia macrotheca var. longistyla | |
| Spergularia macrotheca var. macrotheca | |
| Spergularia marina | saltmarsh sand-spurrey |
| Spergularia media var. media | greater sea-spurrey |
| Spergularia rubra | red sand-spurrey |
| Spergularia villosa | hairy sand-spurrey |
| Stachys ajugoides | hedge nettle |
| Stachys albens | |
| Stachys pycnantha | short-spike hedge nettle |
| Stachys rigida var. quercetorum | |
| Stachys rigida var. rigida | hedge nettle |
| Stebbinsoseris heterocarpa | |
| Stellaria media | common chickweed |
| Stellaria nitens | shining chickweed |
| Stellaria pallida | |
| Stephanomeria elata | |
| Stephanomeria exigua subsp. coronaria | |
| Stephanomeria virgata subsp. pleurocarpa | |
| Streptanthus albidus subsp. peramoenus | most beautiful jewelflower |
| Streptanthus breweri | |
| Streptanthus glandulosus subsp. glandulosus | jewelflower |
| Streptanthus hispidus | Mt. Diablo jewelflower |
| Stylocline gnaphaloides | nest-straw |
| Suaeda californica | California sea-blite |
| Suaeda nigra | bush seepweed |
| Symphoricarpos albus var. laevigatus | snowberry |
| Symphoricarpos mollis | creeping snowberry |
| Symphyotrichum chilense | Pacific aster |
| Symphyotrichum lanceolatum var. hesperium | |
| Symphyotrichum lentum | Suisun Marsh aster |
| Symphyotrichum spathulatum | |
| Symphyotrichum subulatum var. parviflorum | |
| Tamarix parviflora | smallflower tamarisk |
| Tamarix ramosissima | saltcedar |
| Tanacetum parthenium | feverfew |
| Taraxacum erythrospermum | red-seeded dandelion |
| Taraxacum officinale | common dandelion |
| Taraxia ovata | sun cup |
| Tauschia hartwegii | |
| Tellima grandiflora | fringe cups |
| Tetragonia tetragonoides | New Zealand spinach |
| Tetrapteron graciliflorum | hill suncup |
| Thalictrum fendleri var. polycarpum | meadow-rue |
| Thysanocarpus curvipes | fringepod |
| Thysanocarpus laciniatus | lacepod |
| Thysanocarpus radians | |
| Tonella tenella | |
| Torilis arvensis | tall sock-destroyer |
| Torilis nodosa | short sock-destroyer |
| Toxicodendron diversilobum | poison-oak |
| Tragopogon porrifolius | salsify |
| Tribulus terrestris | puncture vine |
| Trichostema lanceolatum | vinegar weed |
| Trifolium albopurpureum | Indian clover |
| Trifolium angustifolium | narrowleaf clover |
| Trifolium barbigerum | bearded clover |
| Trifolium bifidum | Pinole clover |
| Trifolium campestre | hop clover |
| Trifolium ciliolatum | foothill clover |
| Trifolium columbinum | olive clover |
| Trifolium cyathiferum | bowl clover |
| Trifolium depauperatum var. depauperatum | dwarf sack clover |
| Trifolium depauperatum var. truncatum | truncate sack clover |
| Trifolium dichotomum | |
| Trifolium dubium | little hop clover |
| Trifolium fragiferum | strawberry clover |
| Trifolium fucatum | bull clover |
| Trifolium glomeratum | clustered clover |
| Trifolium gracilentum | pinpoint clover |
| Trifolium grayi | Gray's clover |
| Trifolium hirtum | rose clover |
| Trifolium hybridum | alsike clover |
| Trifolium hydrophilum | saline clover |
| Trifolium incarnatum | crimson clover |
| Trifolium macraei | Macrae's clover |
| Trifolium microcephalum | small-head clover |
| Trifolium microdon | thimble clover |
| Trifolium obtusiflorum | clammy clover |
| Trifolium oliganthum | few-flowered clover |
| Trifolium pratense | red clover |
| Trifolium repens | white clover |
| Trifolium subterraneum | subterranean clover |
| Trifolium tomentosum | woolly clover |
| Trifolium variegatum | |
| Trifolium willdenovii | tomcat clover |
| Trifolium wormskioldii | cow clover |
| Triodanis biflora | Venus' looking-glass |
| Triphysaria eriantha subsp. eriantha | butter-and-eggs |
| Triphysaria pusilla | |
| Triphysaria versicolor subsp. faucibarbata | |
| Tropaeolum majus | garden nasturtium |
| Tropidocarpum capparideum | caper-fruited tropidocarpum |
| Tropidocarpum gracile | |
| Turritis glabra | tower mustard |
| Ulmus minor | English elm |
| Uropappus lindleyi | silver puffs |
| Urospermum picroides | false hawkbit |
| Urtica dioica subsp. gracilis | American stinging nettle |
| Urtica dioica subsp. holosericea | hoary nettle |
| Urtica urens | dwarf nettle |
| Vaccinium ovatum | California huckleberry, evergreen huckleberry |
| Verbascum blattaria | moth mullein |
| Verbascum thapsus | woolly mullein |
| Verbena hastata | |
| Verbena lasiostachys var. lasiostachys | |
| Verbena lasiostachys var. scabrida | |
| Verbena litoralis | |
| Verbesina encelioides subsp. exauriculata | golden crownbeard |
| Veronica americana | American brooklime |
| Veronica anagallis-aquatica | water speedwell |
| Veronica arvensis | |
| Veronica catenata | chain speedwell |
| Veronica peregrina subsp. xalapensis | purslane speedwell |
| Veronica persica | Persian speedwell |
| Viburnum ellipticum | western viburnum |
| Vicia americana subsp. americana | American vetch |
| Vicia benghalensis | purple vetch |
| Vicia disperma | |
| Vicia gigantea | giant vetch |
| Vicia hassei | slender vetch |
| Vicia sativa subsp. nigra | common vetch |
| Vicia sativa subsp. sativa | spring vetch |
| Vicia villosa subsp. varia | winter vetch |
| Vicia villosa subsp. villosa | hairy vetch |
| Vinca major | greater periwinkle |
| Viola adunca subsp. adunca | western blue violet |
| Viola douglasii | Douglas violet |
| Viola glabella | stream violet |
| Viola pedunculata | johnny-jump-up |
| Viola purpurea subsp. purpurea | mountain violet |
| Viola purpurea subsp. quercetorum | |
| Viola sempervirens | evergreen violet |
| Viola sheltonii | fan violet |
| Vitis californica | California grape |
| Wyethia angustifolia | narrowleaf mule-ears |
| Wyethia glabra | mules ears |
| Wyethia helenioides | woolly mules ears |
| Xanthium orientale | cocklebur |
| Xanthium spinosum | spiny cocklebur |
| Yabea microcarpa | California hedge parsley |
| Zeltnera davyi | conchalagua |
| Zeltnera muehlenbergii | |