Korall, Petra , Metzgar, Jordan S. , Conant, David S. , Schneider, Harald , Pryer, Kathleen M. .
Phylogeny of scaly tree ferns (Cyatheaceae).
SCALY tree ferns (Cyatheaceae; cyatheoids), with their characteristic tree-like habit and large compound leaves, are a conspicuous component of tropical, subtropical, and south temperate floras. Cyatheoids are the largest group within tree ferns, and all ca. 500 species are distinguished by the presence of scales on the stems and petioles. Here we present a robust phylogeny for scaly tree ferns based on DNA sequence data from five plastid loci (rbcL, rbcL-accD IGS, rbcL-atpB IGS, trnG-trnR, and trnL-trnF). A basal dichotomy resolves Sphaeropteris as sister to all other taxa. Unique scale features separate these two clades: Sphaeropteris has conform scales (with cells of equal size and orientation), whereas all other taxa have marginate scales (cells at the margins are smaller and have a different orientation than cells that are centrally located). The marginate-scale clade consists of a basal trichotomy. These are: i) Cyathea (including Cnemidaria, Hymenophyllopsis, Trichipteris), ii) Alsophila s. str., and iii) Gymnosphaera (previously recognised as a section within Alsophila) and A. capensis. Scaly tree ferns display a wide variation in indusial protection, ranging from absent, to small and disc-shaped, to completely covering the sorus. The evolutionary history of the scaly tree fern indusium is explored.
Log in to add this item to your schedule
1 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA, Department of Phanerogamic Botany, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden,
2 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA
3 - Lyndon State College, Natural Science Department, Lyndonville, Vermont, 05851, USA
4 - University of Goettingen, Department of Systematic Botany, Albrecht von Haller Institute for Plant Sciences, Untere Karspuele 2, Goettingen, D-37073, Germany
scaly tree ferns
Presentation Type: Oral Paper:Papers for Sections
Date: Tuesday, August 1st, 2006
Time: 9:15 AM