SKOG, JUDITH E.1*, JOHN T. MICKEL2, ROBBIN MORAN2, and ELIZABETH A. ZIMMER3. 1Biology Department, George Mason University, Fairfax, VA 22030; 2New York Botanical Garden, Bronx, NY 10458; 3Laboratory for Molecular Systematics, Smithsonian Institution, Washington, DC 20560. - Phylogeny of the fern genus Elaphoglossum based on two chloroplast genes.
Nucleotide sequences from the trnL-F spacer region and the rbcL region
of the chloroplast genome were used to resolve subgeneric
relationships within Elaphoglossum. Fifty-four representative
species from the nine sections, as defined by Mickel and Atehortua,
and six species from outgroup genera Lomariopsis, Bolbitis,
Rumohra and Athyrium were sequenced for the trnL data set
and about half were included in the rbcL data set. The genus
Elaphoglossum is one of the largest and most complex of fern
genera, composed of over 600 species which are nearly all
simple-bladed with acrostichoid sori. The majority of useful taxonomic
characters to date have been vegetative ones, especially those of the
scales and blades. Results from this study support the use of these
characters for definition of the sections and in general support the
definition of the sections outlined by Mickel and Atehortua. However,
new observations from this analysis indicate that there is strong
support for three clades within the section Pachyglossa and
that the subsection Squamipedia is more distinct than
suspected. All species with resinous dots fall within the same
section; there is no support for maintaining Decorata as a
separate section; and the section Amygdalifolia remains unique
indicating there may beat least two origins of hydathodes.
Key words: Elaphoglossum, fern, phylogeny, rbcL, trnL