Sedum sanhedrinum

Berger

Sanhedrin Mountain Stonecrop

G2Imperiled (G2G3) Found in 3 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
High - mediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.1205872
Element CodePDCRA0A260
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRosales
FamilyCrassulaceae
GenusSedum
Concept Reference
Zika, P.F., B.L. Wilson, R.E. Brainerd, N. Otting, S. Darington, B.J. Knaus, and J.K. Nelson. 2018. A review of Sedum section Gormania (Crassulaceae) in western North America. Phytotaxa 368(1): 1- 61.
Taxonomic Comments
The concept of Sedum sanhedrinum of Zika et al. (2018) is narrower than that of S. obtusatum ssp. retusum of Flora of North America Editorial Committee (2009). Zika et al. (2018) state "We clarified the concept of Sedum obtusatum ssp. retusum, and restored it to the rank of species as S. sanhedrinum; It was restricted to Glenn, Lake, Mendocino, and Tehama counties, California". In contrast, Flora of North America Editorial Committee (2009) treated Sedum obtusatum ssp. retusum as occurring in northern California and southwestern Oregon. Zika et al. (2018) further explain "there were many specimens and literature reports of S. obtusatum ssp. retusum that we referred to more northern entities, especially S. oregonense and S. kiersteadiae."
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2021-08-30
Change Date2021-08-30
Edition Date2021-08-30
Edition AuthorsTomaino, A. (2021)
Threat ImpactHigh - medium
Range Extent1000-5000 square km (about 400-2000 square miles)
Number of Occurrences6 - 20
Rank Reasons
Sedum sanhedrinum is known from the the High North Coast Ranges of northern California, in the Yolla Bolly Mountains to Goat Mountain. It is threatened by increasing fire frequency and intensity, and climate change.
Range Extent Comments
Sedum sanhedrinum is known from Glenn, Lake, Mendocino, and Tehama counties, California (Zika et al. 2018).
Occurrences Comments
There are 21 total occurrences, but 9 occurrences are considered historic (CNDDB 2021).
Threat Impact Comments
Over half of the occurrences of Sedum sanhedrinum are within the 2020 August Complex fire (K. Ferguson, pers. comm., 2021). Although the impacts from this fire event are currently unknown, it is likely that Sedum species do not respond well to fire and the intense fires that are becoming more common in California have the potential to kill entire populations (K. Ferguson, pers. comm., 2021). Climate change is also a threat because Sedum sanhedrinum occurs on or near the summits of mountains, restricting it's ability to shift upwards in response to climate change (K. Ferguson, pers. comm., 2021).
Ecology & Habitat

Habitat

Sedum sanhedrinum occurs on serpentine and schist (Zika et al. 2018). Habitats include "rocky slopes, ridgelines, talus, boulder fields, and rocky creek banks, usually in dry to very dry sites, in full sun or, less commonly, in light shade" (Zika et al. 2018).
Terrestrial Habitats
Bare rock/talus/scree
Other Nations (1)
United StatesN2
ProvinceRankNative
CaliforniaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
7 - Natural system modificationsLarge (31-70%)Serious - moderate
7.1 - Fire & fire suppressionLarge (31-70%)Serious - moderate
7.1.1 - Increase in fire frequency/intensityLarge (31-70%)Serious - moderate
11 - Climate change & severe weatherLarge (31-70%)Slight or 1-10% pop. decline
11.1 - Habitat shifting & alterationLarge (31-70%)Slight or 1-10% pop. decline

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (3)
California (3)
AreaForestAcres
Black ButteMendocino National Forest15,461
Elk CreekMendocino National Forest23,182
Snow MountainMendocino National Forest14,457
References (4)
  1. California Natural Diversity Database (CNDDB). 2021. RareFind Version 5.2.14. California Department of Fish and Game, Sacramento.
  2. Ferguson, Katie. Personal communication. Rare Plant Botanist. California Natural Diversity Database, Department of Fish and Wildlife, Sacramento.
  3. Flora of North America Editorial Committee (FNA). 2009. Flora of North America north of Mexico. Vol. 8. Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press, New York. xxiv + 585 pp.
  4. Zika, P.F., B.L. Wilson, R.E. Brainerd, N. Otting, S. Darington, B.J. Knaus, and J.K. Nelson. 2018. A review of <i>Sedum </i>section Gormania (Crassulaceae) in western North America. Phytotaxa 368(1): 1- 61.