Phlox hirsuta, the Yreka Phlox, is a threatened species native to northern California. The species is restricted to five populations, all of which occur on serpentine soil. Given the small number of populations and the edaphic specialization of the species, the viability and longevity of the populations is an important area of study. Multiple factors influence the growth and germination of individual plants , and the amount of growth of an individual plant can fluctuate from year to year. One overlooked aspect of plant growth, in this species, is the soil microbiome, and examining this can shed light on the role of this underground component, in plant growth.