Identity
Unique IDELEMENT_GLOBAL.2.1321555
Element CodePMNAJ010D0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderHydrocharitales
FamilyHydrocharitaceae
GenusNajas
Other Common NamesSouthern Naiad (EN)
Concept ReferenceLes, D.H., E.L. Peredo, U.M. King, L.K. Benoit, N.P. Tlppery, C.J. Ball, and R.K. Shannon. 2015. Through thick and thin: Cryptic sympatric speciation in the submersed genus Najas (Hydrocharitaceae. Molecular Phylogenetics and Evolution 82:15-30
Taxonomic CommentsThis record is for the marginally narrower concept of Najas guadalupensis, excluding the New York endemic, Najas guadalupensis ssp. muenscheri (=N. muenscheri), as recognized by Les et al. (2015), who find, "All collections of N. muenscheri that we have examined conformed genetically with those of the widespread N. canadensis ... Seed measurements of this taxon also fall within the range of those observed for N. canadensis. Chase (1947) determined cytologically that N. muenscheri was a tetraploid, which is yet another observation consistent with all other lines of evidence. Clearly this taxon should be regarded as synonymous with N. canadensis, which has priority of publication." Haynes' treatment in FNA (2000, vol. 22) and Kartesz (1999) recognized the broader concept of N. guadalupensis, accepting muenscheri as a subspecies of it.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-08-01
Change Date2024-08-01
Edition Date2024-08-01
Edition AuthorsJohnson, J. (2024)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank ReasonsNajas guadalupensis is an aquatic annual herb widely distributed in North, Central, and South America. With a large range extent, more than 700 occurrences, abundant habitat, and broad habitat preferences, this species is considered secure.
Range Extent CommentsNajas guadalupensis is widespread in North, Central, and South America between 50° north and 35° south latitudes. Range extent was estimated using herbarium specimens and photo-based observations documented between 1993 and 2024 (GBIF 2024, iNaturalist 2024, SEINet 2024).
Occurrences CommentsBy applying a 1 km separation distance to herbarium records and photo-based observations documented between 1993 and 2024, there are estimated to be more than 700 occurrences rangewide (GBIF 2024, iNaturalist 2024, SEINet 2024).
Threat Impact CommentsAlthough threats are not widely documented, Najas guadalupensis is potentially threatened by development, water pollution, use of aquatic herbicides, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.