D. J. Keil & Elvin
Identity
Unique IDELEMENT_GLOBAL.2.858270
Element CodePDAST4N250
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single state or province
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderAsterales
FamilyAsteraceae
GenusHelianthus
Concept ReferenceKeil, D. J., and M. A. Elvin. 2010. Helianthus inexpectatus (Asteraceae), a tetraploid perennial new species from southern California. Aliso 28: 59-62.
Taxonomic CommentsHelianthus inexpectatus is endemic to California, and morphologically indistinguishable from H. californicus and H. nuttallii ssp. parishii, however, it is believed to be reproductively isolated and geographically restricted and was described in 2010. It should be noted that defining a taxon based on these two criteria, and not necessarily based on morphologic differences too, is in line with the guidance in the Guide for Authors Contributing to the Second Edition of The Jepson Manual (Keil and Elvin 2010).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2021-08-02
Change Date2011-01-10
Edition Date2021-08-02
Edition AuthorsOliver, L. (2011), Treher (2021)
Threat ImpactVery high
Range Extent<100 square km (less than about 40 square miles)
Number of Occurrences1 - 5
Rank ReasonsHelianthus inexpectatus, is known only from its type locality situated along the Santa Clara River in Los Angeles County, California. It grows in a perennially wet seep that is next to land that is slated for major residential development. The Newhall sunflower is highly threatened by the impending development and construction of a bridge that is planned some 100m from the population.
Range Extent CommentsHelianthus inexpectatus is endemic to northern Los Angeles County in California, U.S.A.
Occurrences CommentsThere is a single known occurrences along the Santa Clara River near Newhall.
Threat Impact CommentsThe Newhall sunflower is highly threatened by the impending development and construction of a bridge that is planned some 100m from the population. Specifically, threats to this species from the development and bridge construction include alteration of the hydrologic regime, habitat degradation, invasive species, and trampling (Keil and Elvin 2010).