| Scientific Name | Notes | Rarity Ranks | Common Name |
|---|---|---|---|
| Acmispon strigosus | CNPS-EB: B | strigose trefoil | |
| Ancistrocarphus filagineus | CNPS-EB: C | woolly fishhooks | |
| Arctostaphylos auriculata | CNPS-EB: *A2 State CNPS: 1B.3 Global Rank: G2 CNDDB Rank: S2 | Mount Diablo manzanita | |
| Calochortus pulchellus | CNPS-EB: *A2 State CNPS: 1B.2 Global Rank: G2 CNDDB Rank: S2 | Mount Diablo fairy-lantern | |
| Camissonia contorta | CNPS-EB: C | contorted primrose | |
| Camissoniopsis hirtella | CNPS-EB: B | small primrose | |
| Camissoniopsis intermedia | CNPS-EB: C | small primrose | |
| Camissoniopsis micrantha | CNPS-EB: C | small primrose | |
| Carex globosa | CNPS-EB: B | round-fruited sedge | |
| Clarkia purpurea subsp. viminea | (ssp. quadrivulnera more common | CNPS-EB: A1 | large godetia |
| Crocanthemum scoparium var. vulgare | (formerly Helianthemum scoparium var. vulgare) | CNPS-EB: B | peak rush-rose |
| Deinandra lobbii | (formerly Hemizonia l.) | CNPS-EB: C | three-rayed tarweed |
| Delphinium hesperium subsp. hesperium | CNPS-EB: B | western larkspur | |
| Eriastrum ertterae | CNPS-EB: *A1 State CNPS: 1B.1 Global Rank: G1 CNDDB Rank: S1 CESA Status: CC | Ertter's eriastrum | |
| Eriophyllum lanatum var. achilleoides | CNPS-EB: C | woolly sunflower | |
| Eryngium jepsonii | CNPS-EB: *A2 State CNPS: 1B.2 Global Rank: G2 CNDDB Rank: S2 | ||
| Festuca octoflora | CNPS-EB: A2 | sixweeks grass, slender fescue | |
| Gilia capitata subsp. staminea | CNPS-EB: C | blue field gilia | |
| Gutierrezia californica | CNPS-EB: C | California matchweed | |
| Helianthella castanea | CNPS-EB: *A2 State CNPS: 1B.2 Global Rank: G2 CNDDB Rank: S2 | Diablo helianthella | |
| Helianthus gracilentus | CNPS-EB: B | slender sunflower | |
| Hesperolinon californicum | CNPS-EB: B | California dwarf flax | |
| Lastarriaea coriacea | CNPS-EB: A2 | leather-spineflower, lastarriaea | |
| Leptosiphon pygmaeus subsp. continentalis | (formerly Linanthus p. ssp. c. | CNPS-EB: B | pygmy linanthus, pygmy leptosiphon |
| Lessingia pectinata var. tenuipes | CNPS-EB: A2 | valley lessingia | |
| Malacothamnus hallii | (M. fasciculatus in Jepson Man | CNPS-EB: *A2 State CNPS: 1B.2 Global Rank: G2 CNDDB Rank: S2 | Hall's bush-mallow |
| Navarretia atractyloides | CNPS-EB: A2 | holly-leaved navarretia | |
| Navarretia gowenii | CNPS-EB: *A2 State CNPS: 1B.1 Global Rank: G1 CNDDB Rank: S1 | Lime Ridge navarretia | |
| Navarretia hamata subsp. parviloba | CNPS-EB: A1 | hooked navarretia | |
| Navarretia mellita | CNPS-EB: C | honey-scented navarretia | |
| Navarretia viscidula | CNPS-EB: A2 | sticky navarretia | |
| Nicotiana quadrivalvis | CNPS-EB: B | indian tobacco | |
| Nuttallanthus texanus | CNPS-EB: A2 | blue toadflax | |
| Packera breweri | (formerly Senecio b.) | CNPS-EB: C | Brewer's ragwort, Brewer's butterweed |
| Papaver californicum | CNPS-EB: B | fire poppy | |
| Pectocarya penicillata | CNPS-EB: A2 | northern pectocarya, winged pectocarya | |
| Penstemon centranthifolius | CNPS-EB: B | scarlet bugler | |
| Pentachaeta alsinoides | CNPS-EB: C | tiny pentachaeta | |
| Perideridia oregana | CNPS-EB: A2 | yampah | |
| Pickeringia montana var. montana | CNPS-EB: C | chaparral pea | |
| Piperia michaelii | CNPS-EB: *A2 State CNPS: 4.2 Global Rank: G3 CNDDB Rank: S3 | Michael's rein-orchid | |
| Plagiobothrys tenellus | CNPS-EB: B | Pacific popcornflower, slender popcornflower | |
| Ranunculus occidentalis var. occidentalis | CNPS-EB: B | western buttercup | |
| Rhus aromatica | (formerly R. trilobata) | CNPS-EB: B | skunk bush, skunkbrush, squawbush |
| Scribneria bolanderi | CNPS-EB: B | Scribner's grass | |
| Senecio aronicoides | CNPS-EB: C | rayless ragwort, California butterweed | |
| Stipa cernua | CNPS-EB: C | nodding needlegrass | |
| Stylocline gnaphaloides | CNPS-EB: B | everlasting neststraw, nest-straw | |
| Triodanis biflora | CNPS-EB: A2 | Venus' looking-glass | |
| Wyethia glabra | (W. helenioides is more common | CNPS-EB: C | mule ears |
| Blepharizonia plumosa | CNPS-EB: *A2 State CNPS: 1B.1 Global Rank: G1G2 CNDDB Rank: S1S2 | big tarplant | |
| Cordylanthus pilosus subsp. pilosus | CNPS-EB: B | hairy bird's-beak | |
| Crassula aquatica | CNPS-EB: B | water pygmy-weed | |
| Eriogonum gracile var. gracile | CNPS-EB: C | slender woolly wild buckwheat, slender buckwheat | |
| Eriogonum roseum | CNPS-EB: A2 | wand wild buckwheat, virgate buckwheat | |
| Glyceria leptostachya | CNPS-EB: A1 | narrow manna grass, Davy's mannagrass | |
| Heterotheca sessiliflora subsp. bolanderi | (H. s. ssp. echioides is more | CNPS-EB: C | Bolander goldenaster |
| Juncus mexicanus | CNPS-EB: C | Mexican rush | |
| Lepechinia calycina | CNPS-EB: C | pitcher sage | |
| Lithophragma bolanderi | CNPS-EB: A1 | Bolander starflower | |
| Oenothera deltoides subsp. cognata | CNPS-EB: A2 | desert evening-primrose | |
| Oenothera deltoides subsp. howellii | CNPS-EB: *A2 State CNPS: 1B.1 Global Rank: G5T1 CNDDB Rank: S1 FESA Status: FE CESA Status: CE | Antioch Dunes evening-primrose | |
| Plagiobothrys fulvus var. campestris | CNPS-EB: B | field popcornflower, fulvous popcornflower | |
| Plagiobothrys trachycarpus | CNPS-EB: C | rough-nutlet popcornflower, rough-fruited allocarya | |
| Quercus lobata | CNPS-EB: B | valley oak, roble | |
| Ranunculus canus var. canus | CNPS-EB: C | Sacramento Valley buttercup | |
| Scutellaria tuberosa | CNPS-EB: C | Dannie's skullcap | |
| Stipa pulchra | CNPS-EB: C | purple needlegrass | |
| Trifolium oliganthum | CNPS-EB: C | few-flowered clover | |
| Zeltnera davyi | (formerly Centaurium d.) | CNPS-EB: B | Davy's centaury, conchalagua |