Taxon Report
Eschscholzia rhombipetala Greenediamond-petaled California poppy |
 © 2017 Chris Winchell |
Taxon Summary
Eschscholzia rhombipetala, commonly known as diamond-petaled California poppy, is a annual herb in the Papaveraceae that is found only in California. It occurs within Valley and foothill grassland (alkaline, and clay), growing at elevations from 0 to 975 meters. Eschscholzia rhombipetala is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.Classification
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Scientific Name: |
Eschscholzia rhombipetala Greene |
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Common Name: |
diamond-petaled California poppy |
| Family: | Papaveraceae |
| Element Code: | PDPAP0A0D0 |
| USDA Plants Symbol: | ESRH |
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Synonyms/Other Names: |
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Ecology and Life History
| Lifeform: | annual herb |
| Blooming Period: Mar-Apr | Mar-Apr |
| Elevation: | 0-975 (0-3200) |
| General Habitats: | Valley and foothill grassland |
| Microhabitat: | |
| Microhabitat Details: |
Conservation Status
| CA Rare Plant Rank: | 1B.1 |
| Global Rank: | G1 |
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State Rank: |
S1 |
| State List: | None |
| Fed List: | None |
| Other Status: | BLM_S; SB_CalBG/RSABG; SB_UCBG |
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CRPR Changes: |
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Occurrence Data from the CNDDB
| Total Occurrences: | 15 |
| Element Occurrence Ranks: | |
| Excellent (A) | 1 |
| Good (B) | 4 |
| Fair (C) | 2 |
| Poor (D) | 0 |
| None (X) | 4 |
| Unknown (U) | 4 |
| California Endemic: True | |
| California Counties and Islands: Name (Code) | |
| Alameda (ALA), Colusa (COL)*, Contra Costa (CCA)*, Kern (KRN), San Joaquin (SJQ), San Luis Obispo (SLO), Santa Barbara (SBA), Stanislaus (STA)* | |
| Quads: Name (Quad Code) | |
| Antioch North (3812117)*, Antioch South (3712187), Byron Hot Springs (3712176)*, California Valley (3512031), Chimineas Ranch (3511928), Chimney Canyon (3512012), Clifton Court Forebay (3712175), La Panza (3512032)?*, Las Yeguas Ranch (3511948)*, Lodoga (3912234), Midway (3712165), Patterson (3712142)*, Simmler (3511938), Tracy (3712164), Westley (3712152) | |
Threat List Data from the CNDDB
| Threat List Total: | 7 | |
| EOs with Threat Listed: | Total EOs | % of EOs |
| 7 | 47 % | |
| Agriculture | 3 | 20% |
| Erosion/runoff | 2 | 13% |
| Grazing | 2 | 13% |
| Non-native plant impacts | 2 | 13% |
| Recreational use (non-ORV) | 1 | 6% |
| Feral pigs | 1 | 6% |
| Foot traffic/trampling | 1 | 6% |
Notes
| Rediscovered on Carrizo Plain by David Keil in 1992. Also found at Lawrence Livermore Laboratory Site 300, ALA Co. in 1997. Historical occurrence for SJQ Co. from literature lacks documentation; occurrence from La Panza, SLO Co. (244C) probably misidentified E. lemmonii ssp. lemmonii. See Madroño 47(2):138 (2000) for ALA Co. occurrence information and 50(1):1-7 (2003) for population characteristics information. |
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Threats: |
| Threatened by agriculture and grazing. |
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Taxonomy: |
Citation
California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 23 November 2025].