Surveys and Genetic Diversity Assessments

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Sclerocactus glaucus (Uintah Basin hookless cactus) is a rare cactus that was listed under the Endangered Species Act in 1979. Recently, the species was split into three taxonomic entities: S. brevispinus and S. wetlandicus in Utah; and the remaining S. glaucus in Colorado which is now referred to as the Colorado hookless cactus. Although not examined in detail, a cursory genetic analysis in Colorado found that the DeBeque area portion of the Colorado hookless cactus may be genetically diverse from other geographical areas in Colorado. In addition, the Colorado hookless cactus is known to hybridize with the more common S. parviflorus especially around Whitewater, Colorado. The purpose of this study is to resolve taxonomic questions within the Colorado hookless cactus by examining genetic diversity; assessing taxonomic status; and examining, quantifying, and determining where hybridization is occurring. This study will allow for more effective management of the species because it will identify which populations house the most genetic diversity or have unique genes that will identify which populations warrant conservation, and can further prioritize conservation efforts. At the same time, it will allow managers to understand where hybridization occurs and where ESA protections, as prescribed for the Colorado hookless cactus, are needed. Phacelia formosula (North Park phacelia) is known only from Jackson County, in north central Colorado (within a rectangle spanning 7 miles from east to west and 11 miles north to south). The plant is known from eight element occurrences; two are considered historical because they have not been revisited in over 20 years. Rangewide there are approximately 7,700 individuals, and only two element occurrences have more than 500 individuals (one with approximately 850 individuals and the other with roughly 6000 individuals). A general lack of information pertaining to P. formosula including an accurate assessment of threats makes recovering this species problematic and difficult. Three element occurrences of an unknown Phacelia, with approximately 2500 individuals, were discovered in 2004 in Larimer County and are separated from the Jackson County P. formosula populations by almost 20 miles. The plants from Larimer County are morphologically similar to P. formosula in Jackson County. Taxonomic resolution is needed to determine if the Larimer plants are P. formosula. Genetic and morphological analyses will be used to determine whether these populations should be considered P. formosula. To prevent extinction and reinvigorate recovery efforts for Phacelia formosula this project will: (1) conduct further surveys for the species, (2) collect updated element occurrence information including updating counts of individuals, threats, plant community, and geology, (3) assess morphological diversity of Jackson and Larimer County plants, and (4) assess genetic diversity of the species across its range, as well as within the Larimer County sites. Additional funds are subject to the availibility of funds.

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