TUCKER, SHIRLEY C.1, BENTE B. KLITGAARD2, MARIE FOUGÈRE-DANEZAN3, and ANNE BRUNEAU3.* 1Department of Biology, University of California, Santa Barbara, California 93106 USA; 2Botany Department, The Natural History Museum, Cromwell Road, London, SW7 5BD U.K.; 3Institut de recherche en biologie végétale, Université de Montréal, 4101 Sherbrooke est, Montréal, Québec, Canada H1X 2B2. - Phylogenetic analysis of combined floral ontogenetic and molecular characters in the Detarieae s.l. (Caesalpinioideae: Leguminosae).
Among the four tribes currently recognised in subfamily
Caesalpinioideae, the monophyletic Detarieae s.l. (83 genera) includes
over half of the 161 genera recognised in the subfamily and some of
the most diverse legumes in floral morphology. Recent molecular
analyses suggest particular patterns of relationships among these
taxa, but relationships remain unclear in some groups and further
characters sets are needed. Here we present a phylogenetic analysis of
approximately 45 floral ontogeny characters for 36 species of
caesalpinioid legumes, of which 32 are from the Detarieae s.l. and
four represent outgroup taxa. The floral characters are combined with
DNA sequence data from the chloroplast trnL intron and spacer regions.
The two data sets are not significantly incongruent, although the
position of certain taxa (e.g., Macrolobium, Brownea) differs
between the morphological and molecular analyses. The combined
analysis supports the monophyly of the Detarieae s.l., and suggests
that Barnebydendron, Sindora, Tessmannia, and Schotia
are more basal within the Detarieae s.l. clade. Resolution at the base
of the Detarieae s.l. is obtained mostly from molecular characters,
but the presence of an hypanthium and a gynoecium adnate to the
hypanthium are morphological characters that help resolve
relationships in the basal Detarieae s.l. The remaining species
sampled are grouped in a clade in which resolution is obtained
primarily from morphological data. Most members of the previously
recognised tribe Macrolobieae form a well-supported monophyletic group
derived from other Detarieae, characterised by several morphological
characters (e.g., overlap in timing of initiation of organ whorls).
Overall these analyses suggest that in the Detarieae s.l., bracteole
and sepal characters are particularly informative, while reduction in
number of petals and of stamens occur in parallel in several clades,
and radially symmetrical flowers characterise several unrelated taxa
in the Detarieae s.l.
Key words: Caesalpinioideae, floral ontogeny, Leguminosae, trnL-F DNA sequences