Roadless Areas
Home/Species/ Mahala-mat Ceanothus

Ceanothus prostratus

Benth.

Mahala-mat Ceanothus

G5Secure Found in 79 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.155211
Element CodePDRHA04140
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRhamnales
FamilyRhamnaceae
GenusCeanothus
Other Common Names
Prostrate Ceanothus (EN) prostrate ceanothus (EN)
Concept Reference
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.
Taxonomic Comments
As treated here (following Kartesz, 1999), Ceanothus prostratus includes C. prostratus var. occidentalis and excludes C. confusus and C. pumilus, sometimes (e.g., Kartesz, 1994) treated as subspecies of C. prostratus. FNA (2016, vol. 12) also treats C. confusus and C. pumilus as distinct species and recognizes var. occidentalis as a valid variety of C. prostratus.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-08-04
Change Date2023-08-04
Edition Date2023-08-04
Edition AuthorsGries, D. (1998), rev. C. Nordman (2023).
Threat ImpactLow
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Ceanothus prostratus is known from western Nevada and California north through Oregon to Washington, and it is disjunct in western Idaho. The range extent is estimated to be about 480,000 square kilometers, and there are about 850 occurrences, including about 25 occurrences rangewide which the numbers of plants are described as common, very common, or abundant. Threat impacts may be low, but include loss of habitat due to development. It occurs on many National Forests in California, Nevada and Oregon.
Range Extent Comments
Ceanothus prostratus occurs in the western United States, from the eastern slopes of the Cascade Mountains in Washington, to the Sierra Nevada in California and western Nevada, and disjunct to western Idaho (Idaho Native Plant Society 1992, FNA 2016, CCH2 Portal 2023). In California, it occurs in the Klamath Ranges, North Coast Ranges, high Cascade Range, northern and central high Sierra Nevada, and Modoc Plateau (Hickman 1993). In Nevada, it occurs from the Sierra Nevada Range, from Galena Creek, Franktown, Fishlake and the east side of Peavine Mountain to areas around Lake Tahoe of both Washoe and Carson City Counties, and extending to Spooner Lake, Douglas County (Kartesz 1988). The range extent was estimated to be 480,000 square kilometers using herbarium specimens and photo-based observations documented between 1991 and 2023 (CCH2 Portal 2023, GBIF 2023, iNaturalist 2023).
Occurrences Comments
Based on herbarium records, and photo-based observations documented between 1991 and 2023, and anecdotal evidence, there about 850 occurrences rangewide (CCH2 Portal 2023, GBIF 2023, iNaturalist 2023).
Threat Impact Comments
Threats to Ceanothus prostratus include loss of habitat due to residential, tourism, and recreation related development.
Ecology & Habitat

Habitat

This species grows on sandy or gravelly soils, open flats and gentle slopes, in conifer forests at elevations of 400 to 2700 m (FNA 2016). In Nevada, it grows with yellow pine and red fir (Kartesz 1988); in Idaho, it grows on dry to mesic forest sites, often associated with chaparral, primarily on coarse granitic soils, from mid to high elevations (Idaho Native Plant Society 1992).
Terrestrial Habitats
Forest/WoodlandForest - ConiferShrubland/chaparral
Other Nations (1)
United StatesN5
ProvinceRankNative
IdahoS1Yes
CaliforniaSNRYes
WashingtonSNRYes
OregonSNRYes
NevadaSNRYes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentSmall (1-10%)Serious or 31-70% pop. declineHigh (continuing)
1.3 - Tourism & recreation areasSmall (1-10%)Serious or 31-70% pop. declineHigh (continuing)

—

Plant Characteristics
Economic Value (Genus)Yes
Roadless Areas (79)
California (54)
AreaForestAcres
BackboneShasta-Trinity National Forest11,466
Bald MountainTahoe National Forest5,832
Bald RockPlumas National Forest4,675
Black CinderLassen National Forest239
Bucks LakePlumas National Forest680
Butt Mtn.Lassen National Forest8,217
Callahan FlowModoc National Forest6,618
Castle Crags AShasta-Trinity National Forest113
Castle Crags BShasta-Trinity National Forest1,619
Castle PeakTahoe National Forest14,974
ChanchelullaShasta-Trinity National Forest3,915
ChinquapinShasta-Trinity National Forest22,040
Chips CreekLassen National Forest29,089
Chips CreekPlumas National Forest12,940
Cub CreekLassen National Forest8,643
CypressLassen National Forest3,380
Damon ButteModoc National Forest25,022
Duncan CanyonTahoe National Forest8,621
East GirardShasta-Trinity National Forest27,894
East YubaTahoe National Forest17,968
Granite ChiefTahoe National Forest6,546
Heart LakeLassen National Forest9,349
IshiLassen National Forest21,805
KangarooKlamath National Forest40,617
Keddie RidgeLassen National Forest3,864
Kettle Mtn.Shasta-Trinity National Forest4,589
Lake EleanorShasta-Trinity National Forest397
Middle ForkPlumas National Forest29,278
Middle YubaTahoe National Forest7,379
Mill CreekLassen National Forest7,587
Mokelumne - SprattHumboldt-Toiyabe National Forest613
Mt. EddyShasta-Trinity National Forest7,232
Mt. Shasta AShasta-Trinity National Forest676
Mt. Shasta BShasta-Trinity National Forest2,809
Mystic (CA)Humboldt-Toiyabe National Forest836
North Fork American RiverTahoe National Forest38,495
North Fork Middle Fork American RiverTahoe National Forest11,245
Orleans Mtn.Klamath National Forest49,090
ParsnipModoc National Forest8,485
Poison HoleEldorado National Forest2,627
PyramidEldorado National Forest24,347
Rose - IcelandHumboldt-Toiyabe National Forest1,171
RubiconEldorado National Forest4,872
RussianKlamath National Forest21,771
Ship MountainSix Rivers National Forest11,936
SiskiyouKlamath National Forest54,039
Slate CreekShasta-Trinity National Forest6,636
SnoozerKlamath National Forest23,414
Snow MountainLassen National Forest2,165
Timbered CraterLassen National Forest4,096
Trail LakeLassen National Forest1,124
Weaver BallyShasta-Trinity National Forest829
West GirardShasta-Trinity National Forest37,516
Wild Cattle MtnLassen National Forest4,965
Nevada (10)
AreaForestAcres
Mystic (NV)Humboldt-Toiyabe National Forest5,644
Rose - Alum CreekHumboldt-Toiyabe National Forest853
Rose - Davis Mdw.Humboldt-Toiyabe National Forest2,361
Rose - Dutch LouieHumboldt-Toiyabe National Forest363
Rose - EvansHumboldt-Toiyabe National Forest4,782
Rose - GalenaHumboldt-Toiyabe National Forest3,711
Rose - NortheastHumboldt-Toiyabe National Forest550
Rose - Thomas Mdw.Humboldt-Toiyabe National Forest358
Rose - VerdiHumboldt-Toiyabe National Forest1,155
Rose - Whites CanyonHumboldt-Toiyabe National Forest2,568
Oregon (15)
AreaForestAcres
Badger CreekMt. Hood National Forest847
Brown Mt.Winema National Forest3,117
Castle Rock AppendageUmpqua National Forest4,649
Coleman RimFremont National Forest10,638
MarshWinema National Forest1,226
Medicine Creek AppendageUmpqua National Forest745
Metolius BreaksDeschutes National Forest11,141
Mt. BaileyUmpqua National Forest18,401
Mt. ThielsenWinema National Forest1,153
N. BoundaryWinema National Forest769
Sky Lakes AWinema National Forest3,940
Thirsty Creek AppendageUmpqua National Forest2,255
W. BoundaryWinema National Forest2,345
WaldoDeschutes National Forest4,973
West - South BachelorDeschutes National Forest25,994
References (8)
  1. CCH2 Portal. 2023. Consortium of California Herbaria. Online. Available: https//:www.cch2.org/portal/index.php (accessed 2023).
  2. Flora of North America Editorial Committee (FNA). 2016. Flora of North America north of Mexico. Vol. 12. Magnoliophyta: Vitaceae to Garryaceae. Oxford Univ. Press, New York. xxiv + 603 pp.
  3. Global Biodiversity Information Facility (GBIF). 2023. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2023).
  4. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  5. Idaho Native Plant Society. 1992. Federal candidate (C1 and C2) and listed rare plants of Idaho. unpaginated.
  6. iNaturalist. 2023. Online. Available: https://www.inaturalist.org (accessed 2023).
  7. Kartesz, J.T. 1988. A flora of Nevada. Ph.D. dissertation. Univ. of Nevada, Reno. 3 volumes. 1729 pp.
  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.