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Diplacus ovatus

(Gray) Nesom

Eggleaf Monkeyflower

G2Imperiled (G2Q) Found in 1 roadless area NatureServe Explorer →
G2ImperiledGlobal Rank
HighThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.139575
Element CodePDSCR1B350
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderLamiales
FamilyPhrymaceae
GenusDiplacus
Synonyms
Mimulus bigelovii var. ovatusGrayMimulus ovatus(Gray) N. Holmgren
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
Thompson (2005) considers Mimulus bigelovii var. ovatus to be a synonym of Mimulus cusickii. In contrast, Intermountain Flora recognizes Mimulus ovatus as a distinct species. According to Intermountain Flora (1984), "Some collections of M. ovatus have been treated as a northern extension of M. bigelovii by some and as a southern extension of M. cusickii by others. However, the taxon appears to be more closely allied to the M. mephiticus-M. coccineus-M. densus complex." Nesom (2012) follows Intermountain Flora (1984) in recognizing M. ovatus and M. cusickii as distinct species but in the genus Diplacus. In their treatment of the Flora of North America, Nesom & Tulig (2019) place this species in the genus Diplacus and recognize D. ovatus as a distinct species.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-05-05
Change Date2022-09-01
Edition Date2025-05-05
Edition AuthorsStoner, N., rev. Nachlinger/Maybury (1997); rev. J. Morefield (NVHP, 1999), rev. A. Tomaino (2014), rev. Knapp, W. (2022), rev. Johnson, J. (2025)
Threat ImpactHigh
Range Extent250-1000 square km (about 100-400 square miles)
Number of Occurrences21 - 80
Rank Reasons
Diplacus ovatus is an annual herb that is endemic to a small area of western Nevada and eastern California. It is threatened by recreational uses, off-road vehicle use, and residential, commercial, and/or industrial development.
Range Extent Comments
Diplacus ovatus occurs in the western United States where it is endemic to western Nevada and eastern California. It extends along the eastern Sierra front from Peavine Mountain in Washoe County to Douglas County, Nevada, and Alpine County, California in the south. Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are 35 occurrences rangewide (GBIF 2025, iNaturalist 2025, NatureServe 2025, RARECAT 2025, SEINet 2025).
Threat Impact Comments
Threats to this species include motorized and non-motorized recreation, residential, commercial, or industrial development, and invasive plants (NDNH 2014, NatureServe 2025). Occurrences on private lands around Reno and Carson City are at risk from residential and commercial development. Occurrences on lands managed by Carson City have been impacted by the construction of trails, a disc golf course, and an off-road vehicle open use area, and other recreational facilities in Diplacus ovatus habitat are planned (Lumos & Associates 2024, Carson City Parks, Recreation, & Open Space Department 2025). Sheep grazing on the west side of Carson City may be a potential threat.
Ecology & Habitat

Habitat

This species grows on dry slopes in sagebrush, pinyon-juniper, and Jeffrey pine communities at 1300-1700 (occasionally up to 2400) m elevation. The habitat is characterized as "dry to somewhat moist, often barren, loose, sandy to gravelly slopes derived from siliceous sinter deposited by hot springs in the sagebrush zone, or from highly acidic hydrothermally altered andesite or rhyolite deposits supporting sparse yellow pine woodlands within the pinyon-juniper zone, or possibly on sandy alkaline valley floor deposits in the sagebrush zone, sometimes on adjacent roadsides or washes" (Morefield 2001).
Terrestrial Habitats
Forest/WoodlandWoodland - ConiferShrubland/chaparralBarrens
Other Nations (1)
United StatesN2
ProvinceRankNative
NevadaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)
2 - Agriculture & aquacultureSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
2.3 - Livestock farming & ranchingSmall (1-10%)Moderate or 11-30% pop. declineHigh (continuing)
6 - Human intrusions & disturbanceLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesLarge (31-70%)Moderate or 11-30% pop. declineHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)
8.1.1 - Unspecified speciesLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)

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Plant Characteristics
DurationANNUAL
Economic Value (Genus)No
Roadless Areas (1)
Nevada (1)
AreaForestAcres
Jobs Peak (NV)Humboldt-Toiyabe National Forest1,342
References (17)
  1. Carson City Parks, Recreation, & Open Space Department. 2025. Park Facilities Website. https://www.carson.org/government/departments-g-z/parks-recreation-open-space/parks-and-places
  2. Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren. 1984. Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Vol. 4, Subclass Asteridae (except Asteraceae). New York Botanical Garden, Bronx. 573 pp.
  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). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  5. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  6. Johnson, Janel. 2018. Current Knowledge and Conservation Status of <i>Erythranthe carsonensis </i>Fraga (Phrymaceae), the Carson Valley monkeyflower. Online. Available: <a href="http://heritage.nv.gov/sites/default/files/library/Carson%20Valley%20monkeyflower%20final%20report%202018.pdf">http://heritage.nv.gov/sites/default/files/library/Carson%20Valley%20monkeyflower%20final%20report%202018.pdf</a> accessed 10 Jun 2019.
  7. Kartesz, J.T. 1988. A flora of Nevada. Ph.D. dissertation. Univ. of Nevada, Reno. 3 volumes. 1729 pp.
  8. 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.
  9. Lumos & Associates. 2024. Carson River Trail System - Phase 3 - Prison Hill West. For Carson City Parks, Recreation, & Open Space Department. https://www.carson.org/home/showpublisheddocument/88777/638471276559270000
  10. Morefield, J.D., editor. 2001. Nevada rare plant atlas [with rare plant fact sheets]. Available as a pdf file at: http://heritage.nv.gov/atlas/atlas.html. Compiled by the Nevada Natural Heritage Program, Carson City, for the U.S. Fish and Wildlife Service, Reno, Nevada.
  11. NatureServe. 2022. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  12. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  13. NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2024. Version: 1.1.1 (released Oct 01, 2024).
  14. Nesom, G.L. 2012b. Three varieties raised to specific rank in <i>Diplacus </i>(Phrymaceae). Phytoneuron 47: 1-6.
  15. Nevada Division of Natural Heritage (NDNH). 2014. Element Subnational Ranking Form: <i>Mimulus ovatus</i> in Biotics 5 database. NatureServe, Arlington, Virginia (accessed 1 Sep 2022).
  16. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  17. Thompson, D.M. 2005. Systematics of <i>Mimulus </i>subgenus <i>Schizoplacus</i> (Scrophulariaceae). Syst.Bot. Monogr. 75: 1–213.