F. Gibson
Identity
Unique IDELEMENT_GLOBAL.2.129508
Element CodePMAGA010F0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderAsparagales
FamilyAsparagaceae
GenusAgave
Concept ReferenceKartesz, 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 Date2024-06-28
Change Date2013-09-30
Edition Date2024-06-28
Edition AuthorsMaybury, K. (1996), rev. A. Olivero (2003), rev. S. Schuetze (2012), rev. A. Tomaino (2013), rev. C. Nordman (2024).
Threat ImpactHigh
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences6 - 80
Rank ReasonsMurphey Agave (Agave murpheyi) occurs in a very restricted geographic area in southern Arizona and northern Sonora, where it has persisted in previously agricultural sites, after its cultivation declined centuries ago, around 1450 CE. Each distinct population may consist of fewer than 50 genetic individuals. Its isolated nature and the small number of individuals in a population, make this species vulnerable to extinction. While it was thought to be stable in 2012, decline has been documented since then. Threats include loss of habitat from urbanization, residential development, conversion of agriculture land, and reservoir expansion, increased regional drought (which may be exacerbated by climate change), and disturbances to habitat such as livestock grazing and trampling, and recreation activities, including ORV impacts.
Range Extent CommentsMurphey Agave (Agave murpheyi) occurs in western North America, and it is regionally endemic to the Sororan Desert in Arizona in the southwestern United States, and Sonora in northwestern Mexico. It occurs in south-central Arizona, in Gila, Maricopa, Pinal, and Yavapai counties, and in northern Sonora, and is associated with historic or present-day human habitation, especially with pre-Columbian agricultural and settlement features (Gentry 1982, AGFD 2003). Range extent was estimated to be 36,000 square kilometers, using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1993 and 2024 in Arizona, and including a couple locations from the 1980s in Sonora where it is considered to remain extant, while there is a lack of recent presence data (AGFD 2003, Villaseñor 2016, GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are about 22, and between six and 80 occurrences of Murphey Agave rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024). In the 1995, there were as many as 60 known sites (AFGD 2003), although some of these sites may have been closer than 1 km to each other, and others are likely remote, and might not have been verified more recently. Fifteen sites of 20 which were most accessible were relocated and censused in 2022 and 2023 (Riccio 2023). There were considered to be more than 25 populations in 2012 using Fertig's 2009 ranking system, modified (Laurenzi and Spence 2012).
Threat Impact CommentsThreats to Murphey Agave include loss of habitat from urbanization, residential development, conversion of agriculture land, and reservoir expansion, increased regional drought (which may be exacerbated by climate change), and disturbances to habitat such as livestock grazing and trampling, and recreation activities, including ORV impacts (AGFD 2003, Riccio 2023). Illegal collection for cultivation and small mammal predation also pose threats to the species (AGFD 2003).