Erythranthe exigua

(A. Gray) G.L. Nesom & N.S. Fraga

San Bernardino Mountain Monkeyflower

G2Imperiled Found in 3 roadless areas NatureServe Explorer →
G2ImperiledGlobal Rank
High - mediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.155318
Element CodePDSCR1B140
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderLamiales
FamilyPhrymaceae
GenusErythranthe
Synonyms
Mimulus exiguusGray
Other Common Names
San Bernardino Mountain monkeyflower (EN)
Concept Reference
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.
Taxonomic Comments
The Flora of North America (vol. 17 2019) transfers Mimulus exiguus to Erythranthe exigua; these represent the same concept for the element.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-05-13
Change Date1984-06-26
Edition Date2024-05-13
Edition AuthorsD. Gries, Rev. A. Treher (2013), Eberly (2024)
Threat ImpactHigh - medium
Range Extent5000-20,000 square km (about 2000-8000 square miles)
Number of Occurrences6 - 80
Rank Reasons
Erythranthe exigua is a small tap-rooted annual herb that occurs in San Bernardino County, California, USA, and Baja California, Mexico. In California, this species is found in a unique habitat, the pebble plains, that is host to many rare species but highly sensetive to soil disturbance. This species is threatened by development, recreation, mining, erosion, and alterations to site hydrology. Many historical occurrences in California are on private land, where development has occurred and remains a threat to any existing sites; it is likely that some of these occurrences are extirpated. More information is needed for occurences in Mexico.
Range Extent Comments
Erythranthe exigua occurs in the San Bernardino Mountains of southern California, USA, and in the Sierra de Juárez and Sierra de San Pedro Mártir of Baja California, Mexico (Villaseñor 2016, CCH2 2024). Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1983 and 2024 (GBIF 2024, iNaturalist 2024, NatureServe 2024).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1983 and 2024, it is estimated that there are 19 occurrences rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024). In California, occurrences are delineated using a small separation distance to classify 22 occurrences, but 15 of those are historical (over 20 years old) (CNDDB 2024). There are numerous sites last documented prior to 1983 that occur in protected areas or seemingly remote locations that may still be extant.
Threat Impact Comments
Occurrences on private land in California are threatened by new development and the long term impacts of habitat fragmentation in highly developed areas. Most extant occurrences are in San Bernadino National Forest where the primary threat is recreation, including trampling by hikers and off road vehicle (ORV) use. The pebble plain habitat where this species occurs is especially threatened by ORV use. Mining, past degradation and future activities, is a threat on private and public lands. Other threats include alterations to site hydrology; erosion post fire; and pipeline, transmission line, and road maintenance (CNDDB 2024). Some occurrences in Mexico are nearby roads but the landownership is not known for all occurrences (CCH2 2024). Regional threats to the mountains of northern Baja California include mining, logging and cattle ranching but these may be of low intensity. These mountainous regionas are relatively intact (Riemann and Exequiel 2007).
Ecology & Habitat

Habitat

This species grows on gentle slopes, along streamlets, in vernal depression, and in runoff areas on mesic, clay substrates and is found in open areas or margins of openings, such as meadows or pebble plain habitats (areas of dense clay soils armored by a lag gravel of quartzite pebbles that form openings of low cover and are dominated by herbaceous, cushion-forming species), within Chaparral, Yellow Pine Forest, and Upper Montane Coniferous Forest communities at elevations of 1,800 to 2,630 m (FNA 2019, CCH2 2024, CNDDB 2024).
Terrestrial Habitats
Forest/WoodlandForest - ConiferForest EdgeShrubland/chaparralGrassland/herbaceousBarrens
Palustrine Habitats
TEMPORARY POOLHERBACEOUS WETLANDRiparian
Other Nations (1)
United StatesN1
ProvinceRankNative
CaliforniaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentSmall (1-10%)Extreme - seriousHigh (continuing)
1.1 - Housing & urban areasSmall (1-10%)Extreme - seriousHigh (continuing)
2 - Agriculture & aquacultureRestricted - smallModerate - slightHigh (continuing)
2.3 - Livestock farming & ranchingRestricted - smallModerate - slightHigh (continuing)
2.3.2 - Small-holder grazing, ranching or farmingRestricted - smallModerate - slightHigh (continuing)
3 - Energy production & miningRestricted - smallSerious - slightHigh - low
3.2 - Mining & quarryingRestricted - smallSerious - slightHigh - low
4 - Transportation & service corridorsRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
4.1 - Roads & railroadsRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
5 - Biological resource useRestricted (11-30%)UnknownHigh (continuing)
5.3 - Logging & wood harvestingRestricted (11-30%)UnknownHigh (continuing)
6 - Human intrusions & disturbanceLarge (31-70%)Serious - slightHigh (continuing)
6.1 - Recreational activitiesLarge (31-70%)Serious - slightHigh (continuing)

Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (3)
California (3)
AreaForestAcres
Granite PeakSan Bernardino National Forest450
Heartbreak RidgeSan Bernardino National Forest4,455
SugarloafSan Bernardino National Forest8,206
References (10)
  1. California Natural Diversity Database (CNDDB). 2024. RareFind Version 5.3.0. California Department of Fish and Game, Sacramento.
  2. CCH2 Portal. 2024. Consortium of California Herbaria. Online. Available: https//:www.cch2.org/portal/index.php (Accessed 2024).
  3. Flora of North America Editorial Committee (FNA). 2019. Flora of North America north of Mexico. Vol. 17: Magnoliophyta: Tetrachondraceae to Orobanchaceae. Oxford Univ. Press, New York. xxiv + 737 pp.
  4. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  5. Hickman, J. C., ed. 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, CA. 1400 pp.
  6. iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
  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. Riemann, H., and E. Exequiel. 2007. Endemic regions of the vascular flora of the peninsula of Baja California, Mexico. Journal of Vegetation Science 18(3): 327-336.
  9. Skinner, M.W., and B.M. Pavlik, eds. 1997 (1994). Inventory of rare and endangered vascular plants of California. 1997 Electronic Inventory Update of 1994 5th edition, California Native Plant Society, Special Publication No. 1, Sacramento.
  10. Villaseñor, J.L. 2016. Checklist of the native vascular plants of Mexico. Revista Mexicana de Biodiversidad 87: 559-902.