Fig 2. Relative read counts summed across all OTUs for each plant taxonomic assignment.

The counts are represented in phylogenetic context with the size of the circle at each node proportional to the (square-root transformed) counts per million (cpm) reads across all samples combined. Assignments were made at five taxonomic ranks as described in the methods. Counts for interior nodes reflect progressively greater taxonomic uncertainty in the underlying OTUs; they do not represent sums of counts attributed to the leaves of that node.