ALVAREZ, AIDA1,2* and KENNETH CAMERON1. 1The Lewis B. and Dorothy Cullman Program for Molecular Systematics Studies, The New York Botanical Garden, Bronx, New York 10458-5126; 2The City University of New York, Herbert H. Lehman College, Department of Biological Sciences, Bedford Park Boulevard West, Bronx, New York 10468. - Phylogenetic analysis of Gomphichis and the subtribe Prescottiinae (Orchidaceae).
Gomphichis contains about 23 species of terrestrial orchids.
The genus has a continuous distribution from Costa Rica to Bolivia
with disjunct species in the Guayana Highlands and southeastern
Brazil. Gomphichis and its close relatives Aa,
Altensteinia, Myrosmodes, Porphyrostachys,
Prescottia and Stenoptera have been placed within the
subtribe Prescottiinae, tribe Cranichideae (Dressler, 1993). The
Prescottiinae include most of the Neotropical terrestrial orchids that
flourish at high and middle elevations in the major mountain chains of
Central and South America. Phylogenetic relationships within the
subtribe Prescottiinae are unclear and generic limits among some of
their members are questionable. In order to provide the first
phylogenetic hypothesis for Gomphichis and the Prescottiinae,
we generated a molecular phylogeny based on ITS sequence data. Ingroup
taxa included most members of the Prescottiinae, except
Stenoptera. Outgroup taxa consisted of representatives from
three of six subtribes currently recognized in Cranichideae.
Preliminary analyses support the monophyly of Gomphichis and
suggest the paraphyly of the Prescottiinae (sensu Dressler, 1993).
Further molecular and morphological studies are underway to
circumscribe Gomphichis and define an expanded concept of the
subtribe Prescottiinae.
Key words: Gomphichis, ITS, Neotropics, Orchidaceae, Phylogeny, Prescottiinae