J Syst Evol ›› 2014, Vol. 52 ›› Issue (2): 161-174.DOI: 10.1111/jse.12073

• Research Articles • Previous Articles     Next Articles

Towards the natural classification of tectarioid ferns: Confirming the phylogenetic relationships of Pleocnemia and Pteridrys (eupolypods I)

1Hong-Mei LIU* 2Li-Juan HE 3Harald SCHNEIDER   

  1. 1(Shenzhen Laboratory of Southern Subtropical Plant Diversity, Fairylake Botanical Garden, Shenzhen & Chinese Academy of Sciences, Shenzhen 518004, China)
    2(State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China)
    3(Department of Life Sciences, Natural History Museum, London, SW7 5BD, UK)
  • Received:2013-08-21 Published:2014-01-29

Abstract: The phylogenetic relationships of the two derived fern genera Pleocnemia and Pteridrys were considered ambiguous even with molecular evidence from previous studies. In the present study we determined the phylogenetic position based on five plastid DNA regions, namely atpA, atpB, rbcL, the rps4 + rps4–trnS intergenic spacer, and the trnL-F region, and an expanded taxonomic coverage including several accessions of each of the two genera. Our results showed that the monophyletic genus Pleocnemia belonged to the Dryopteridaceae and was not related to the Tectariaceae, as it had been in the past. Pleocnemia was found to be closely related to the bolbitidoid and lastreopsioid ferns. The monophyletic genus Pteridrys was found to be sister to a clade comprising Triplophyllum and Tectarias.l. Thus, the placement of this genus into Tectariaceae was confirmed. The sinus teeth, the unique similarity shared by Pleocnemia and Pteridrys, evolved independently in the two genera. Both genera appeared to have diverged from their closest extant relatives at least since the Eocene, whereas the crown group ages indicated radiation events in the Late Miocene for both genera.

Key words: derived ferns, divergence time estimates, Dryopteridaceae, morphological convergence, phylogenetics, Tectariaceae.