Lucia Lohmann

São Paulo, Brazil

Ph.D., University of Missouri-St.Louis, 2003

MS, University of Missouri-St.Louis, 1998
BS Universidade de São Paulo, 1995

Research Interest:

Lianas account for a third of leaf biomass of tropical forests, contribute between 20-25% of the floristic diversity of neotropical forests and are an important source of food for many animals. Yet they have been little studied, and little is known concerning their taxonomy, distribution, ecology and evolution.

My research focuses on the systematics, evolution, ecology and biogeography of the tribe Bignonieae (family Bignoniaceae), the most diverse and abundant group of lianas in the neotropics. Apart from being important components of tropical forests, members of Bignonieae (360 species) are also known for their showy flowers (e.g., the trumpet-creeper) associated with different pollinators, for unusual extra-floral nectaries associated with herbivore defense, and for diverse dispersal mechanisms.

The major goal of my Ph.D. research was to reconstruct the evolutionary history of the tribe Bignonieae using phylogenetic systematics. This allowed me to identify patterns of morphological and ecological diversification and biogeography within this tribe. By delimiting monophyletic lineages based on a phylogenetic framework, the evolution of characters could be better understood, generic limits could be reconsidered and a predictive classification was produced.

In order to address those questions, I conducted fieldwork in Brazil, Peru, Surinam, and Costa Rica during which I saw and collected 250 of the 350 recognized Bignonieae species. Field data, together with a study of herbarium specimens of all known Bignonieae species allowed me to reevaluate morphological characters and to define species-groups (provisional genera) on the basis of putative synapomorphies. I then used cpDNA (ndhF) and nDNA (PepC) sequence data to reconstruct the phylogeny of Bignonieae and thus, test the monophyly of my provisional genera and of the traditionally recognized Bignonieae genera. My sampling scheme included 1/3 of all Bignonieae species (120 out of 360 species).

The phylogeny of Bignonieae was only partially congruent with the previous generic classification of the tribe. Thus, a new classification based on phylogenetic data and morphological synapomorphies was proposed. I named a clade as a genus whenever it was a well supported monophyletic clade, and recognizable by a morphological synapomorphy. The evolution of morphological characters was mapped onto the combined molecular tree to evaluate their utility as generic characters. This suggested that several characters traditionally used to circumscribe genera are highly homoplastic. In contrast, several characters such as wood anatomy, prophylls of the axillary buds and stem section are synapomorphies of well supported clades.