| Abstract Detail
Pteridology George, Lisa [1], Pryer, Kathleen M. [1], Kao, Tzu-Tong [1], Huiet, Layne [1], Windham, Michael D. [1]. The Long and Winding Road: Exploring the relationships of Cheilanthes brandegeei (Pteridaceae) . Among the xeric-adapted cheilanthoid ferns (Pteridaceae; Cheilanthoideae), the relationships of Cheilanthes brandegeei, a fern endemic to the Baja Peninsula of Mexico, have been controversial. Pteridologists have proposed intrageneric alliances with other Cheilanthes species from regions as diverse as the Peruvian Andes and Africa. Emphasizing its strongly fractiferous petioles, Tryon and Tryon (1983) associated this non-farinose taxon with a small group of largely farinose species now generally included in Notholaena. Subsequent molecular analyses of rbcL by Cranfill (unpubl.) suggested that C. brandegeei might be related to the genus Bommeria, an early-diverging lineage of cheilanthoid ferns phylogenetically distant from both Cheilanthes s.s. and Notholaena. In this study, we investigate the relationships of C. brandegeei using a three-gene (atpA, rbcL, trnG-R) plastid analysis coupled with detailed morphological studies. Phylogenetic analyses strongly support the placement of C. brandegeei as the sister taxon to all Bommeria species and identify three morphological features that appear to unite members of this expanded bommeriid clade: leaf indument of acicular trichomes, reticulate to cristate perispore morphology, and lateral position of gametophyte meristem initiation. Because of its distinctive morphology within the bommeriid clade, we propose the new genus Baja to accommodate this species and name its sole species, Baja brandegeei. This study again illustrates the challenges of using traditional characters such as leaf architecture, sporangial distribution, and indusium morphology in cheilanthoid classification due to extensive homoplasy in these characters.
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1 - Duke University, Department of Biology, Box 90338, Durham, NC, 27708, USA
Keywords:
Baja California
cheilanthoid ferns
plastid phylogeny
Pteridaceae.
Presentation Type: Oral Paper
Session: 5, Pteridology I
Location: 108/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 9:30 AM
Number: 5007
Abstract ID:867
Candidate for Awards:Edgar T. Wherry award |
