Home/Species/ Dunn's Mariposa Lily

Calochortus dunnii

Purdy

Dunn's Mariposa Lily

G3Vulnerable Found in 2 roadless areas NatureServe Explorer →

G3VulnerableGlobal Rank

High - mediumThreat Impact

Identity

Unique IDELEMENT_GLOBAL.2.144933

Element CodePMLIL0D0C0

Record TypeSPECIES

ClassificationSpecies

Classification StatusStandard

Name CategoryVascular Plant

Endemicoccurs (regularly, as a native taxon) in multiple nations

KingdomPlantae

PhylumAnthophyta

ClassMonocotyledoneae

OrderLiliales

FamilyLiliaceae

GenusCalochortus

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.

Conservation Status

Rank Method Rank calculation - Biotics v2

Review Date2024-04-19

Change Date2024-04-19

Edition Date2024-04-19

Edition AuthorsD. Gries, rev. Treher (2017), rev. Eberly and Bittman (2024)

Threat ImpactHigh - medium

Range Extent1000-5000 square km (about 400-2000 square miles)

Number of Occurrences21 - 80

Rank Reasons

Calochortus dunnii is a perennial herb that occurs in western North America in San Diego County, California, USA, and Baja California, Mexico. There are at least 34 occurrences that are mostly found on public lands managed by the U.S. Forest Service and BLM. Threats are variable depending on the site and include competitive non-native plants, development, off road vehicles, and road construction.

Range Extent Comments

Calochortus dunnii occurs in the western North America, where it is found in San Diego County, California, USA, and Baja California, Mexico (Villaseñor 2016) where It was documented in the vicinity of Ensenada (M. Delgado-Fernández (2023) via iNaturalist 2024).

Occurrences Comments

There are at least 34 occurrences, with 33 in California, and at least one recently documented occurrence in Mexico by (CNDDB 2024, iNaturalist 2024).

Threat Impact Comments

Threats vary site to site with a limited scope across occurrences and include competitive non-native plants, development, off road vehicles, and road construction. Potential threats may also include border enforcement activities, ranch activities, wildflower picking, and cattle grazing (CNDDB 2024).

Ecology & Habitat

Habitat

This species grows in closed-cone coniferous forest, valley and foothill grasslands, and chaparral on rocky gabbro or metavolcanic soils at elevations of 215 to 1,700 m (CNDDB 2024).

Terrestrial Habitats

Forest/WoodlandForest - ConiferShrubland/chaparral

Other Nations (1)

United StatesN3

Province	Rank	Native
California	S3	Yes

Threat Assessments

Threat	Scope	Severity	Timing
2 - Agriculture & aquaculture	Restricted - small	Serious - slight	High (continuing)
2.3 - Livestock farming & ranching	Restricted - small	Serious - slight	High (continuing)
2.3.2 - Small-holder grazing, ranching or farming	Restricted - small	Serious - slight	High (continuing)
4 - Transportation & service corridors	Restricted - small	Serious - slight	High (continuing)
4.1 - Roads & railroads	Restricted - small	Serious - slight	High (continuing)
5 - Biological resource use	Small (1-10%)	Unknown	High (continuing)
5.2 - Gathering terrestrial plants	Small (1-10%)	Unknown	High (continuing)
5.2.1 - Intentional use (species being assessed is the target)	Small (1-10%)	Unknown	High (continuing)
6 - Human intrusions & disturbance	Restricted - small	Moderate or 11-30% pop. decline	High (continuing)
6.1 - Recreational activities	Restricted - small	Moderate - slight	High (continuing)
6.2 - War, civil unrest & military exercises	Restricted - small	Moderate - slight	High (continuing)
7 - Natural system modifications	Restricted - small	Unknown	High (continuing)
7.1 - Fire & fire suppression	Restricted - small	Unknown	High (continuing)
7.1.1 - Increase in fire frequency/intensity	Restricted - small	Unknown	High (continuing)
8 - Invasive & other problematic species, genes & diseases	Large - restricted	Moderate or 11-30% pop. decline	High (continuing)
8.1 - Invasive non-native/alien species/diseases	Large - restricted	Moderate or 11-30% pop. decline	High (continuing)
8.1.1 - Unspecified species	Large - restricted	Moderate or 11-30% pop. decline	High (continuing)

Plant Characteristics

DurationPERENNIAL

Economic Value (Genus)No

Roadless Areas (2)

California (2)

Area	Forest	Acres
Eagle Peak	Cleveland National Forest	6,481
No Name	Cleveland National Forest	4,897

References (7)

California Department of Fish and Game. 2000. Natural Diversity Database (RareFind 2), Version 2.1.2, January 25, 2000. Downloaded in 2003.
California Natural Diversity Database (CNDDB). 2024. RareFind Version 5.3.0. California Department of Fish and Game, Sacramento.
Flora of North America Editorial Committee (FNA). 2002a. Flora of North America north of Mexico. Vol. 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford Univ. Press, New York. xxvi + 723 pp.
iNaturalist. 2024. Online. Available: https://www.inaturalist.org (accessed 2024).
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.
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.
Villaseñor, J.L. 2016. Checklist of the native vascular plants of Mexico. Revista Mexicana de Biodiversidad 87: 559-902.

Calochortus dunnii

Habitat

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