FIGURE LEGENDS:
Figure 1: Herbarium specimens are often mounted with roots intact and nodules (inset) can be found on even the oldest specimens. The nodule pictured here was take from specimen 324040 collected in 1962 from Walla Walla, Washington. Photo credit: Water Fertig (plant specimen) and Layla Taylor-Spriggs (inset)
Figure 2: We had no growth on any of our negative controls (A) and historic leaf controls (B). We had leaf endophytes grow from our fresh controls, however only for a subset of the media types (C). We had low probability of growth for plates streaked with crushed nodules from 1950 (D) and no probability of growth on plates streaked with nodules from 1974 (E) and 1986 (F). Probability of growth was high for more recent specimen nodules including 2004 (G) and 2015 (H). Probability of growth was nearly 100% with contemporary nodules (I).
Figure 3: Sanger sequencing (done on 42% of our isolates) revealed isolates from four genera isolated from our 1950 sample. We identified isolates from 12 genera in our two nodules taken from the 2004 specimen. We found isolates from three genera from our nodule taken from a 2015 specimen.