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Field Guide


Clay Phacelia

Clay Phacelia (Phacelia argillacea)
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Phacelia argillacea

NatureServe conservation status

Global (G-rank): G1
State (S-rank): S1

Utah Wildlife Action Plan status

  • SGCN

External links


General information

Phacelia argillacea is a federally listed as endangered species known from a single canyon in Utah County, Utah where it grows on steep hillside in the sparse juniper-pinyon community and mountain brush community in the Green River formation.  Clay Phacelia have indescribable blue violet colored petals forming their bell shaped flowers. The flowers form along branching stems, each unrolling as the flowers bloom. The leaves are deeply lobed and have hairs on the surface.

Phacelia argillacea is one of Utah's rarest plants and also one of the rarest plants in the United States. The known populations occur on private land which limits the protection available for this endangered Phacelia.

Description

Phacelia argillacea is a federally listed as endangered species known from a single canyon in Utah County, Utah where it grows on steep hillside in the sparse juniper-pinyon community and mountain brush community in the Green River formation.  Clay Phacelia have indescribable blue violet colored petals forming their bell shaped flowers. The flowers form along branching stems, each unrolling as the flowers bloom. The leaves are deeply lobed and have hairs on the surface.

Phacelia argillacea is one of Utah's rarest plants and also one of the rarest plants in the United States. The known populations occur on private land which limits the protection available for this endangered Phacelia.

Phenology

Flowers from June to August.

Diagnostic characteristics

Phacelia argillacea resembles P. glandulosa, and can be positively identified both by location and by some distinct characteristics of the leaves and the seeds. P. argillacea is known from Spanish Fork Canyon in Utah County, while P. glandulosa is known from Grand and Uintah Counties. The leaves of P. argillacea have hairs which are nonglandular, while P. glandulosa has leaves with glandular hairs. When in fruit, the seeds of P. argillacea are less than 2.4 mm long and 1.1 mm wide while the seeds of P. glandulosa are larger measuring  2.4–3.3 mm long and 1.1–1.4 mm wide. 

Species range

This species is known from two different locations near Tucker in Spanish Fork Canyon, in Utah County.

Threats or limiting factors

The inheriently small distribution (Spanish Fork Canyon, Utah County, Utah) and population size of clay phacelia may increase the species’ vulnerability to threats (USFWS 2019). This species is mainly threatened by loss of individuals and habitat destruction caused by native mammal herbivory; road, utility line, and railway maintenance; invasive plant species, and climate change (USFWS 2019). Additional threats include grazing, recreation, erosion, loss of genetic diversity, and disease (USFWS 2019).

Taxonomy

No, this species does not have taxonomic discrepancies