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Sedum laxum

(Britt.) Berger

Lax Stonecrop

G5Secure (G5?) Found in 28 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.1212836
Element CodePDCRA0A270
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
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 laxum in Zika et al. (2018) excludes S. laxum var. eastwoodiae (which is treated as S.eastwoodiae) and S. laxum var. flavidum (which is treated as S. flavidum). "Sedum flavidum and Sedum eastwoodiae were removed from S. laxum sensu stricto, and raised to species rank, based on floral characters" (Zika et al. 2018).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-08-02
Change Date2023-08-02
Edition Date2023-08-02
Edition AuthorsRusso, M. (1989), rev. A. Tomaino (2023)
Threat ImpactUnknown
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences81 to >300
Rank Reasons
Sedum laxum occurs in northwest California and southwest Oregon. There are a large number of occurrences estimated, 81 to over 300, but researchers found that some populations disappeared in recent years. Threats are apparently low but do include road construction, logging, and climate change.
Range Extent Comments
Sedum laxum is known from northwest California and southwest Oregon (Zika et al. 20180, Jepson Flora Project 2023, Oregon State University 2023). Range extent was estimated using herbarium specimens, NatureServe Network occurrence data, and photo-based observations, collected between 1992 and 2023 (CCH2 Portal 2023, GBIF 2023, iNaturalist 2023, NatureServe 2023).
Occurrences Comments
By applying a 1 km separation distance to herbarium records, NatureServe Network occurrence data, and photo-based observations documented between 1992 and 2023, it is estimated that there are between 81 and 300 occurrences rangewide (CCH2 Portal 2023, GBIF 2023, iNaturalist 2023, NatureServe 2023). If records older than 1992 are included, the number of estimated occurrences is greater than 300.
Threat Impact Comments
Threats for Sedum laxum ssp. heckneri were considered low in California (R. Bittman, pers. comm., 2018). In Oregon, road construction causing rockslides and logging are mentioned as threats in three occurrences of S. laxum ssp. heckneri. Threats are not documented for Sedum laxum ssp. laxum. Zika et al. (2018) mention the following for the genus Sedum section Gormania in western North America. "Changes in temperature, precipitation, snow cover, drought frequency or duration could potentially affect the reproduction of Sedum taxa in the next 50 years, especially in the drier interior ranges" (Zika et al. 2018).
Ecology & Habitat

Habitat

Sedum laxum occurs on cliffs and rock outcrops, road cuts, boulder fields, rocky slopes, often on serpentine, but also on argillite, chert, and shale (Zika et al. 2018, Jepson Flora Project 2023, Oregon State University 2023).
Terrestrial Habitats
Bare rock/talus/screeCliff
Other Nations (1)
United StatesN5
ProvinceRankNative
CaliforniaSNRYes
OregonS5Yes
Threat Assessments
ThreatScopeSeverityTiming
4 - Transportation & service corridors———
5 - Biological resource use———
5.3 - Logging & wood harvesting———
11 - Climate change & severe weather———

—

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (28)
California (26)
AreaForestAcres
Bell QuinbyShasta-Trinity National Forest11,556
Black ButteMendocino National Forest15,461
Blue Creek Rare ISix Rivers National Forest12,134
Condrey Mtn.Klamath National Forest2,923
Cow CreekShasta-Trinity National Forest22,627
Elk CreekMendocino National Forest23,182
GrindstoneMendocino National Forest26,031
Indian CreekKlamath National Forest5,011
KangarooKlamath National Forest40,617
KellySix Rivers National Forest5,195
Monkey CreekSix Rivers National Forest9,017
Mt. LassicSix Rivers National Forest6,643
North Fork SmithSix Rivers National Forest37,898
Orleans Mtn.Klamath National Forest49,090
Orleans Mtn. BSix Rivers National Forest17,183
PacksaddleSix Rivers National Forest3,862
PortugueseKlamath National Forest18,915
RussianKlamath National Forest21,771
Ship MountainSix Rivers National Forest11,936
SiskiyouKlamath National Forest54,039
Siskiyou ASix Rivers National Forest1,017
Siskiyou BSix Rivers National Forest18,871
Slide CreekSix Rivers National Forest11,458
SnoozerKlamath National Forest23,414
Snow MountainMendocino National Forest14,457
UnderwoodSix Rivers National Forest6,591
Oregon (2)
AreaForestAcres
North KalmiopsisSiskiyou National Forests91,560
South KalmiopsisSiskiyou National Forests104,477
References (12)
  1. Bittman, Roxanne. Personal Communication. Botanist, California Natural Diversity Database, Sacramento, Calif.
  2. CCH2 Portal. 2023. Consortium of California Herbaria. Online. Available: https//:www.cch2.org/portal/index.php (accessed 2023).
  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. Global Biodiversity Information Facility (GBIF). 2023. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2023).
  5. iNaturalist. 2023. Online. Available: https://www.inaturalist.org (accessed 2023).
  6. Jepson Flora Project (eds.) 2023. Jepson eFlora. Online. Available: https://ucjeps.berkeley.edu/eflora/ (accessed 2023).
  7. Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
  8. Kartesz, J.T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. First edition. In: Kartesz, J.T., and C.A. Meacham. Synthesis of the North American Flora, Version 1.0. North Carolina Botanical Garden, Chapel Hill, N.C.
  9. Meyers, S.C., T. Jaster, K.E. Mitchell, T. Harvey, and L.K. Hardison, editors. 2020. Flora of Oregon. Volume 2: Dicots A-F. Botanical Research Institute of Texas, Fort Worth, TX. 861 pp.
  10. NatureServe. 2023. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  11. Oregon State University (OSU). 2023. Oregon Flora website. Oregon State University Herbarium at Oregon State University. Online. Available: https://oregonflora.org/ (accessed 2023).
  12. 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.