New Data on the Taxonomic Status of Ditrichum plumbicola Crundw.(Bryophyta) and its Relation to D. lineare (sw.) Kindb. Based on the trnL-F Region of the cpDNA

Ditrichum plumbicola is a species from heavy metal rich soil in Britain and Germany described only some 30 years ago. It resembles morphologically D. lineare, from which it differs by shorter leaves and plane leaf margins. To test whether D. plumbicola is genetically distinct, a molecular study has been undertaken using the nuclear ribosomal ITS and plastid trnL-F DNA regions. The phylogenetic tree derived from 8 populations of D. lineare and four German populations of D. plumbicola shows that D. plumbicola intermingled in the branch of D. lineare. D. plumbicola representatives are variously positioned and not genetically well separated. It can therefore be supposed that D. plumbicola is merely an ecotype of D. lineare with slight morphological differences and not a good species. Ditrichum plumbicola is therefore reduced to a variety to D. lineare.