I may be a decade or two behind the times, but the Penstemon species found on USWildflowers.com have been moved from Scrophulariaceae – the Figwort family  – to Plantaginaceae – the Plantain family. The change in classification was based on genetic research done in the 1990’s, and published around the turn of the century. Wide acceptance of this classification change occurred over the next decade, but many publications have continued to list the genus in Scrophulariaceae. That oversight has now been corrected on USWildflowers.com.

It’s interesting that the folks who drove the change in classification of many species formerly in Scrophulariaceae  wanted the family in which Penstemon was placed to be called Veronicaceae because that was an older name, but that was apparently rejected by the international committee charged with settling naming disputes, interestingly because it was too old – earlier than the 1789 cutoff for conserved names.