RANKER, T. A.1*, J. M. GEIGER1, S. C. KENNEDY1, A. R. SMITH2, C. H. HAUFLER3, and B. S. PARRIS4. 1University Museum & EPO Biology, University of Colorado, Boulder, CO, 80309; 2University Herbarium, University of California, Berkeley, CA 94720; 3Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045; 4Fern Research Foundation, 21 James Kemp Place, Kerikeri, Bay of Islands, New Zealand. - Phylogenetic systematics of the Hawaiian endemic genus Adenophorus (Grammitidaceae).
Adenophorus s.l. is one of only three endemic genera of ferns
in Hawaii. It has been distinguished from other genera of
Grammitidaceae primarily because of distinctive glandular paraphyses
and other laminar hairs. The uniqueness of those features, however,
has been questioned and other Indo-Pacific taxa may be close
relatives. In particular, Chrysogrammitis musgraviana was
proposed as being the closest Indo-Pacific relative. Hawaiian species
have either been classified as a single genus with two subgenera or as
two similarly circumscribed genera: Adenophorus s.s., with
variously deeply dissected leaves and no root buds, and
Oligadenus, with entire or shallowly-to-deeply lobed leaves and
with root buds. We investigated the phylogenetic relationships of the
species of Adenophorus s.l. with one another and with 56 other
species of the Grammitidaceae from throughout the range of the family,
including other Hawaiian taxa. We obtained DNA sequences of three
cpDNA regions: atpB, rbcL, and the trnL-trnF
spacer. Phylogenetic analyses of these data yield the following
hypotheses: 1) Adenophorus s.l. is monophyletic; 2) the
Hawaiian endemic Grammitis tenella is the sister taxon to
Adenophorus s.l.; 3) Adenophorus s.s. is monophyletic
and arose from within subgenus Oligadenus; 4) subgenus
Oligadenus is paraphyletic; and, 5) C. musgraviana is
not closely related to the Hawaiian clade. The geographical origin of
the group remains unresolved because the strongly supported sister
clade contains species from Costa Rica, Panama, Brazil, and La
Réunion.
Key words: Adenophorus, ferns, Grammitidaceae, Hawaii, phylogenetics, systematics