Hughes's phacelia
Walter Fertig iNaturalist observation 2014; Walter Fertig iNaturalist observation 2014
Phacelia hughesii
NatureServe conservation status
Global (G-rank): G2
State (S-rank): S1
Utah Wildlife Action Plan status
- SGCN
External links
General information
P. hughesii is a biennial herb in the Boraginaceae family known in Utah only from Washington County. It produces visually distinct white flowers with dark purple veins and can be seen flowering among gypsum knolls with rabbitbrush (Chrysothamnus sp.), sagebrush (Artemisia sp), and other desert shrubs. While considered rare throughout its range, its limited occurrence in Utah makes it an especially important conservation target in this state.
Description
P. hughesii is an herb that produces several reddish branching stems covered in stiff hairs and reaching 30 cm in height. P. hughesii tends not to produce basal leaves, instead growing lanceolate leaves 0.6-2.3 cm x 2.2-4.3 mm from the stems. Leaves are somewhat rolled backwards from the margins towards the underside, and are covered in minute, coarse hairs. Clusters of flowers grow from the sides and ends of stems, with flowers measuring 4.5 mm, 3.5 mm of which is made up of a floral tube. The flowers are white with purple veins, with violet anthers.
Phenology
This species is biennial, completing its flowering cycle over two years. It blooms May to September.
Diagnostic characteristics
This species is closely related to P. constancei, but differs in having shorter flowers with dark veins, coarse, non-glandular hair on the leaves and stems, and small lanceolate leaves that have a raised ventral mid-vein. When comparing seeds of the two species, P. hughesii seeds are also more corrugated.
Species range
Previously, this species was known only from outcrops of the Harrisburg Formation in Mohave County, Arizona. However, it was first observed in Utah in 2016 just north of the state line in Washington County, in an outcropping of the Moenkopi Formation. It is estimated to occupy 72 square kilometers across its range, though only a very small fraction of its habitat is in Utah.
Map
Habitat
The typical soil from which P. hughesii grows is derived from limestone, though it is also found growing in gypsum soils, indicating a preference for calcium rich minerals. It is found in association with mixed desert shrub communities. It can be found at elevations ranging from 1420-1810 m.
Threats or limiting factors
The main threats are from habitat degradation due to grazing, energy and mineral extraction, drought, and road maintenance. Almost all observations of this plant in the Utah Rare Plant Database reported farming and ranching as a threat at the only known occurrence of this plant in Utah. May also be impacted by the proposed Lake Powell Pipeline project.
Taxonomy
No, this species does not have taxonomic discrepancies