Taxon Report
Ivesia webberi GrayWebber's ivesia |
 © 2007 Steve Matson |
Taxon Summary
Ivesia webberi, commonly known as Webber's ivesia, is a perennial herb in the Rosaceae that is found in California and elsewhere. It occurs within Great Basin scrub (volcanic ash), Lower montane coniferous forest, and Pinyon and juniper woodland, growing at elevations from 1000 to 2075 meters. Ivesia webberi is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.Classification
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Scientific Name: |
Ivesia webberi Gray |
|
Common Name: |
Webber's ivesia |
| Family: | Rosaceae |
| Element Code: | PDROS0X0Q0 |
| USDA Plants Symbol: | IVWE |
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Synonyms/Other Names: |
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Ecology and Life History
| Lifeform: | perennial herb |
| Blooming Period: May-Jul | May-Jul |
| Elevation: | 1000-2075 (3280-6810) |
| General Habitats: | Great Basin scrub, Lower montane coniferous forest, Pinyon and juniper woodland |
| Microhabitat: | Gravelly (sometimes), Sandy (sometimes) |
| Microhabitat Details: |
Conservation Status
| CA Rare Plant Rank: | 1B.1 |
| Global Rank: | G2 |
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State Rank: |
S1 |
| State List: | None |
| Fed List: | FT |
| Other Status: | SB_CalBG/RSABG; USFS_S |
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CRPR Changes: |
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Occurrence Data from the CNDDB
| Total Occurrences: | 13 |
| Element Occurrence Ranks: | |
| Excellent (A) | 2 |
| Good (B) | 4 |
| Fair (C) | 2 |
| Poor (D) | 1 |
| None (X) | 2 |
| Unknown (U) | 2 |
| California Endemic: False | |
| California Counties and Islands: Name (Code) | |
| Lassen (LAS), Plumas (PLU), Sierra (SIE) | |
| Quads: Name (Quad Code) | |
| Chilcoot (3912072), Constantia (3912081), Crescent Mills (4012018), Dog Valley (3912051), Evans Canyon (3912061), Little Mud Flat (4012042), Meadow Valley (3912181), Quincy (3912088)*, Spring Garden (3912087), Taylorsville (4012017) | |
Threat List Data from the CNDDB
| Threat List Total: | 12 | |
| EOs with Threat Listed: | Total EOs | % of EOs |
| 12 | 92 % | |
| Non-native plant impacts | 7 | 53% |
| ORV activity | 7 | 53% |
| Grazing | 7 | 53% |
| Improper burning regime | 3 | 23% |
| Road/trail construction/maint. | 3 | 23% |
| Other | 3 | 23% |
| Development | 3 | 23% |
| Foot traffic/trampling | 2 | 15% |
| Agriculture | 1 | 7% |
| Dam/Inundation | 1 | 7% |
| Recreational use (non-ORV) | 1 | 7% |
| Logging | 1 | 7% |
Notes
| Known in CA only from Sierra and Dog valleys. Threatened in NV. |
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Threats: |
| Threatened by vehicles, and potentially by development, grazing, alteration of fire regimes, and non-native plants. |
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Taxonomy: |
| See Proceedings of the American Academy of Arts and Sciences 10:71 (1874) for original description. |
Citation
California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 29 November 2025].