Developmental and Structural Section
Michelangeli, Fabian A. , Stevenson, Dennis Wm. .
Comparative morphology, anatomy and development of ant-domatia in Neotropical Melastomataceae.
Ant-domatia are present more than 70 species of Neotropical Melastomataceae, occurring in nine genera of the tribes Blakeeae and Miconieae. Two species of Miconia have hollow stem domatia (primary domatia), while all other species have domatia in the petiole or the base of the blade (secondary domatia). Previous phylogenetic analyses have shown that secondary domatia have evolved in parallel several times within the family and that loss of domatia has also occurred. Comparative morphological and anatomical studies of ant-domatia of four different genera were carried out by sectioning leaves, petioles and meristems at various developmental stages. Secondary domatia differ greatly across species and can develop completely immersed in the base of the leaf blade, partially immersed in the leaf blade, at the petiole apex, or at the base of the petiole at its point of attachment on the stem. This last type of domatium is often referred to in the literature as “stem domatium,” even though they are not formed by hollow stems but rather by petiole bases. Anisophylly is strongly correlated with domatia that are immersed in the leaf base. Differences in the position of domatia seem to be tied to the timing of their development and the location of meristematic activity. For example, “stem” domatia of Clidemia ciliata start developing once the leaves have completely expanded, the domatia of Maieta guianensis which are immersed in the leaf blade develop during leaf expansion, and domatia at the apex of the petiole in Tococa guianensis develop before leaf expansion. The differences in morphology, anatomy, and development of domatia will be discussed in a phylogenetic context.
1 - New York Botanical Garden, Institute of Systematic Botany, 200th St & Kazimiroff Blvd, Bronx, New York, 10458, USA
2 - New York Botanical Garden, Cullman Program for Molecular Systematics Studies, 200th St. & Southern Blvd., Bronx, New York, 10458-5126, USA
Presentation Type: Paper
Location: Alpine A (Snowbird Center)
Date: Wednesday, August 4th, 2004
Time: 4:30 PM