The Correct Name for Didymodon Validus (Bryophyta, Pottiaceae) at Variety Rank

摘要

Didymodon validus Limpr. is not universally recognised as a species in its own right but it is often considered a variety, D. rigidulus Hedw. var. validus (Limpr.) Düll. The epithet validus was used at varietal rank only in 1923, as Barbula rigidula (Hedw.) Mitt. var. valida (Limpr.) Broth., but this taxon was actually recognised as a variety, B. rigidula var. gigantea Schlieph. ex Warnst., already in 1904, and this name is lectotypified herein. Accordingly, the transfer of this variety to Didymodon Hedw., as D. rigidulus var. giganteus (Schlieph. ex Warnst.) Ochyra & Bednarek-Ochyra, comb. nov., is effected. This is the correct name for this Central European-Central Asian montane taxon at variety rank. Didymodon validus is considered a new synonym of D. rigidulus var. giganteus.