In
1991,
W. George Schmid published his landmark book, The Genus
Hosta which made a number of changes in
the way hostas are categorized. Before that time, there had been
quite a bit of confusion and disagreement on the taxonomy of the
genus.
Through this detailed tome, Schmid helped to organize the
taxonomy of the genus in several ways. One of the most
significant changes was shifting some plants from the status of
species into cultivars. In most cases, the determining factor
was that plants such as Hosta fortunei or Hosta
tokudama could not be shown to have ever existed in the
wilds of Japan, Korea or China. His determination was that they
were either selections or hybrids from gardens or nurseries.
Therefore, these and several others were reclassified as
cultivars whose names should be H. 'Fortunei'
and H. 'Tokudama'.