XVI International Botanical Congess
The Haplolepidae, with a unique peristome, forms a major lineage within the arthrodontous mosses. Relationships of the four orders within the Haplolepidae are explored using 3 cpDNA regions - rbcL, rps4, trnL(UAA) - trnF(GAA) and morphology. Parsimony analyses of independent and combined data sets reveal new, robust relationships: an expanded, monophyletic Calymperaceae nested within the Dicranales, not the Pottiales, the Leucobryaceae s.s. and Dicnemonaceae nested within the Dicranaceae, a polyphyletic Paraleucobryaceae, and the Fissidentaceae within the Dicranales. The specialized costa with medial chlorocysts and surrounding leucocysts has evolved multiple times within the Dicranales.