| Scientific Name | Notes | Rarity Ranks | Common Name |
|---|---|---|---|
| Amsinckia lunaris | CNPS-EB: *A2 State CNPS: 1B.2 Global Rank: G3 CNDDB Rank: S3 | bent-flowered fiddleneck | |
| Calochortus umbellatus | CNPS-EB: *A2 State CNPS: 4.2 Global Rank: G3? CNDDB Rank: S3? | Oakland star-tulip | |
| Helianthella castanea | CNPS-EB: *A2 State CNPS: 1B.2 Global Rank: G2 CNDDB Rank: S2 | Diablo helianthella | |
| Micropus amphibolus | (historical - 1955) | CNPS-EB: *A1x State CNPS: 3.2 Global Rank: G3G4 CNDDB Rank: S3S4 | Mount Diablo cottonseed, Mt. Diablo cottonweed |