Botanists are sometimes described as lumpers or splitters, depending on tendencies to combine or divide groups of plants they're describing. Solomon's-seal and its close relatives like lily-of-the-valley are among the many species that have now been split from the once large lily family. The varieties of smooth Solomon's-seal, however, are now combined in one species. So I guess you could say it's a split lump. This certainly adds to the dissonance we older wildflower enthusiasts feel when trying to reconcile our favorite old manuals with modern terminology.