The genus Symphytum (comfrey) in the Czech Republic. I. S. tuberosum agg.

A review of genus Symphytum in the Czech Republic is presented, incl. an identification key and remarks on its distribution and ecology. The first part of this review is focused on the Symphytum tuberosum agg. This group is taxonomically difficult and includes high polyploids. Two dominant ploidy levels were found in the Czech Republic: tetraploid (S. tuberosum subsp. angustifolium) and dodecaploid (S. tuberosum subsp. tuberosum). S. tuberosum subsp. angustifolium shows clear affinity to the margins of the Pannonian basin and was found only in Moravia. The more common and widespread S. tuberosum subsp. tuberosum was demonstrated to occur in the entire country, but is almost absent from the Czech part of Carpathian Mts. A detailed overview of morphological characters useful for identification of these taxa, their ecological differentiation and distribution maps are presented.