Identity
Unique IDELEMENT_GLOBAL.2.138126
Element CodePDFAB2A0Q0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderFabales
FamilyFabaceae
GenusAcmispon
SynonymsAnisolotus mearnsii(Britton) A.HellerHosackia mearnsiiBrittonLotus mearnsii(Britt.) GreeneOttleya mearnsii(Britton) D. D. Sokoloff
Other Common NamesMearns Birds-foot-trefoil (EN) Mearns’s deervetch (EN)
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.
Taxonomic CommentsFNA (2023, vol. 11) recognizes Lotus as native to Eurasia, with taxa native to North American treated as Acmispon or Hosackia. FNA (2023, vol. 11) treats Lotus mearnsii in the genus Acmispon as A. mearnsii.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-10-28
Change Date1999-08-12
Edition Date2024-10-25
Edition AuthorsBroaddus, Lynn (1991), rev. N. Ventrella (2024)
Threat ImpactUnknown
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences21 - 80
Rank ReasonsThis species is a perennial forb occurring on limestone plateaus, mesas, ridges, slopes, washes, sandy tuffaceous soils, and calcareous or lacustrine deposits within open ponderosa pine, juniper, oak-pinyon-juniper woodlands, grasslands, or desert scrub. It is known from a relatively small geographic area in Coconino, Maricopa, Navajo, and Yavapai counties of Arizona. There are an estimated 36 occurrences of this species, which are potentially threatened by exotic invasive plants, cattle grazing, wildfire, recreation, rights-of-way development and maintenance, and urban development. Information is lacking on the life history of this species, including phenology and reproduction, along with threats, abundance, distribution, and trends.
Range Extent CommentsThis species occurs in the western United States in Coconino, Maricopa, Navajo, and Yavapai counties of Arizona (FNA 2023). Range extent was estimated using herbarium specimens and photo-based observations collected between 1993 and 2024 (iNaturalist 2024, SEINet 2024). See individual entries for distribution details about the two varieties.
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens and photo-based observations documented between 1993 and 2024, it is estimated that there are 36 occurrences rangewide (iNaturalist 2024, SEINet 2024).
Threat Impact CommentsSpecific threats to this species are unknown. However, threats to species and ecosystems of the lower Verde River region of central Arizona, where var. equisolensis occurs, include exotic invasive plants such as Bromus rubens and Schismus spp., cattle grazing, wildfire, and climate change (Larson-Whittaker 2020). Additional potential threats include recreation, rights-of-way development and maintenance, and urban development.