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Field Guide


Thompson’s flameflower

Thompson’s flameflower (Phemeranthus thompsonii)
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Photo by Andrey Zharkikh; Braydon Lake ; Braydon Lake
Andrey Zharkikh iNaturalist observation 2021; Braydon Lake iNaturalist image; Braydon Lake iNaturalist observation 2024

Phemeranthus thompsonii

NatureServe conservation status

Global (G-rank): G2
State (S-rank): S2

Utah Wildlife Action Plan status

  • SGCN

External links


General information

Phemeranthus thompsonii is endemic to the Cretaceous Cedar Mountain Formation in Emery County, Utah. It is a perennial herb that can be found in shallow, gravelly soils among pinyon-juniper and ponderosa pine communities. These plants are low, clump forming with fleshy stems. The flowers occur in open cymes and have pink petals. Phemeranthus thompsonii is treated as a seperate species by Welsh in Utah Flora, but there has been consideration of merging with P. validulus. Further sampling would be needed to reveal absolute molecular or morphological distinctions at a varietal level. 

Description

Phemeranthus thompsonii is endemic to the Cretaceous Cedar Mountain Formation in Emery County, Utah. It is a perennial herb that can be found in shallow, gravelly soils among pinyon-juniper and ponderosa pine communities. These plants are low, clump forming with fleshy stems. The flowers occur in open cymes and have pink petals. Phemeranthus thompsonii is treated as a seperate species by Welsh in Utah Flora, but there has been consideration of merging with P. validulus. Further sampling would be needed to reveal absolute molecular or morphological distinctions at a varietal level. 

Phenology

Flowers starting mid July throughout August. 

Diagnostic characteristics

Phemeranthus thompsonii main differences between other species in the genus is the erect-ascending branches with spreading stems and peduncles  rather than mat-forming growth habits, leaf size of 8-32 mm long, flowers in terminal cymes, and 10 stamens. 

Species range

Colorado Plateau; Cedar Mountain, Emery County, Utah, USA.

Threats or limiting factors

Potential threats include recreational disturbances, road construction and the nearby presence of radio towers (Franklin 2005). As a succulent, there is the possibility of collection for cultivation. Drought may also be impacting this species.

Taxonomy

Yes, this species has taxonomic discrepancies