MICHELANGELI, FABIAN A. Cullman Program for Molecular Systematics, American Museum of Natural History, New York, NY 10024. - Phylogenetic relationships in the Miconieae: Evidence from morphological and ITS sequence data.
Miconieae is the most diverse tribe of the Melastomataceae, with 28-30
genera and over 2200 species. The tribe is characterized by its fleshy
fruits and partially to totally inferior ovaries. The tribe is found
throughout the Neotropics, and it is composed mostly of small trees
and shrubs, although a small number of taxa might be climbing or
herbaceous. The genus Miconia accounts for close to half of the
species diversity in the tribe, while most other genera have less than
30 species, and six are monotypic. In spite of its diversity and
abundance the phylogenetic relationships within the tribe are poorly
understood. Morphological and sequence data from ITS 1 & 2 were
gathered and analyzed separately, as well as combined, in order to
assess the phylogenetic relationships within the Miconieae. Using
exemplars of the tribe Merianieae as outgroup, most species of
Miconia are resolved as basal within the tribe, with most of
the sections of this genus not recovered as monophyletic. Most
terminal-flowered genera seem to be derived from within Miconia
(such as Tococa and Leandra), as it is Clidemia
(an axillary flowered genus with over 160 species). The remaining
cauliflorus and axillary-flowered taxa seem to be derived from within
Clidemia. Henriettella and Henriettea form a
clade, but neither genus seems to be monophyletic. Lastly,
Bellucia and Loreya are resolved as sister taxa, derived
from within Clidemia. Several taxa in the tribe present
reductions of the anther appendages and the calyx, which seem to have
been independently derived in several occasions. Because current
taxonomic classifications rely on these characters, several groups are
not monophyletic. This analysis is being used as the base for a better
understanding of character evolution within this diverse group
Key words: anther evolution, ITS, Melastomataceae, Miconieae, Myrtales, phylogenetics