| Scientific Name | Notes | Rarity Ranks | Common Name |
|---|---|---|---|
| Calochortus pulchellus | CNPS-EB: *A2 State CNPS: 1B.2 | Mount Diablo fairy-lantern | |
| Argemone munita | CNPS-EB: A1 | chicalote, prickly poppy | |
| Berberis aquifolium var. dictyota | CNPS-EB: A1 | Jepson's mahonia | |
| Helianthella castanea | CNPS-EB: *A2 State CNPS: 1B.2 | Diablo helianthella | |
| Phacelia ramosissima | CNPS-EB: A2 | branching phacelia | |
| Trifolium columbinum | CNPS-EB: C | olive clover | |
| Horkelia californica var. frondosa | CNPS-EB: B-PV | leafy horkelia | |
| Leptosiphon pygmaeus subsp. continentalis | (formerly Linanthus p. ssp. c. | CNPS-EB: B | pygmy linanthus, pygmy leptosiphon |