Inference of Ploidy Level in 19th-Century Historical Herbarium Specimens Reveals the Identity of Five Acorus Species Described by Schott

Heinrich Wilhelm Schott (1794–1865) was one of the pioneering researchers in taxonomy species-rich monocot family Araceae. He described numerous new plant species various genera, including Acorus, which is currently segregated as a monogeneric and order occupying position sister to rest monocots. While describing his mostly used characters that are considered low, if any, taxonomic value. His descriptions lack some key including, for obvious reasons, chromosome numbers. Therefore, Schott’s concepts cannot be properly interpreted according current understanding diversity even though names must examined implementation principle nomenclatural priority. The only way resolving identity through identification type specimens among historical herbarium collections, by inferring taxonomically significant missing descriptions. On basis collections Komarov Botanical Institute, St. Petersburg (LE), we were able infer ploidy levels materials describe Acorus triqueter (diploid, Siberia), A. tatarinowii (tetraploid, China), nilaghirensis India), griffithii Bhutan), commutatus Bhutan). Leaf anatomy pollen stainability cytotype markers. All five belong polymorphic calamus complex comprises important medicinal plants. Detailed analyses provided.