The genus Lobelia contains over 400 separate species in the world with >25 species in The United States. Species of Lobelia, in addition to many other plant species form symbiotic relationships with fungi in soil to better absorb nutrients. In this study, we examined the differences among Lobelia species in root colonization by symbiotic fungi. This could help provide a better understanding of the habitat types where different species occur and how geographically widespread they are.

Whole plants from across the United States were collected for this study, and roots were stained with trypan blue and mounted on microscope slides. Amounts and types of fungal colonization inside of each root were then quantified. These data were then compared among samples within species and among species.

It was found that Lobelia siphilitica and Lobelia cardinalis, two species that cover large ranges of The United States, had lower percentages of colonization than other species examined. The only aquatic species, Lobelia dortmanna, also had low rates of colonization. Three species (Lobelia brevifolia, Lobelia glandulosa, and Lobelia puberula) that inhabit Southeast American states, such as Florida, had the highest rates of brown septate fungi. Further comparisons of data collected will be needed before making formal conclusions on similarities in colonization and species relatedness.