Taxon Report
Holocarpha macradenia (DC.) GreeneSanta Cruz tarplant |
 © 2011 Dylan Neubauer |
Classification
|
Scientific Name: |
Holocarpha macradenia (DC.) Greene |
|
Common Name: |
Santa Cruz tarplant |
| Family: | Asteraceae |
| Element Code: | PDAST4X020 |
| USDA Plants Symbol: | HOMA |
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Synonyms/Other Names: |
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Ecology and Life History
| Lifeform: | annual herb |
| Blooming Period: Jun-Oct | Jun-Oct |
| Elevation: | 10-220 (35-720) |
| General Habitats: | Coastal prairie, Coastal scrub, Valley and foothill grassland |
| Microhabitat: | Clay (often), Sandy |
| Microhabitat Details: |
Conservation Status
| CA Rare Plant Rank: | 1B.1 |
| Global Rank: | G1 |
|
State Rank: |
S1 |
| State List: | CE |
| Fed List: | FT |
| Other Status: | SB_CalBG/RSABG; SB_UCBG |
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CRPR Changes: |
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Occurrence Data from the CNDDB
| Total Occurrences: | 37 |
| Element Occurrence Ranks: | |
| Excellent (A) | 1 |
| Good (B) | 4 |
| Fair (C) | 8 |
| Poor (D) | 5 |
| None (X) | 16 |
| Unknown (U) | 3 |
| California Endemic: True | |
| California Counties and Islands: Name (Code) | |
| Alameda (ALA)*, Contra Costa (CCA)*, Marin (MRN)*, Monterey (MNT), Santa Cruz (SCR) | |
| Quads: Name (Quad Code) | |
| Briones Valley (3712282), Felton (3712211), Hayward (3712261)*, Laurel (3712118), Oakland West (3712273)*, Prunedale (3612176), Richmond (3712283)*, San Rafael (3712285)*, Santa Cruz (3612281), Soquel (3612188), Watsonville East (3612186), Watsonville West (3612187) | |
Threat List Data from the CNDDB
| Threat List Total: | 10 | |
| EOs with Threat Listed: | Total EOs | % of EOs |
| 29 | 78 % | |
| Development | 19 | 51% |
| Grazing | 12 | 32% |
| Non-native plant impacts | 11 | 29% |
| Other | 4 | 10% |
| Foot traffic/trampling | 4 | 10% |
| Road/trail construction/maint. | 3 | 8% |
| Recreational use (non-ORV) | 2 | 5% |
| ORV activity | 2 | 5% |
| Mining | 1 | 2% |
| Agriculture | 1 | 2% |
Notes
| All extant CCA Co. occurrences (465B, 466A) are introduced; nearly half have failed. Last remaining natural population in the S.F. Bay Area extirpated by development in 1993. Seriously threatened by urbanization, agriculture, non-native plants, and lack of appropriate ecological disturbance. See Fremontia 5(4):15-16 (1978) for species account. |
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Threats: |
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Taxonomy: |
Citation
California Native Plant Society, Rare Plant Program. 2024. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 29 December 2024].