At the Montreal Botanical Garden two collections have been extensively used in the past for research: Begonia and Araceae. Three main research projects have been conducted so far using the Begonia collection (more than 230 species and 300 cultivars). (A) The comparative anatomy and development of the Begonia flower and leaf. This project has allowed us to explain the nature of the inferior ovary and the mode of appearance of the asymmetrical leaf in this genus. (B) The comparative analysis of leaf micro-anatomical characters, types of trichomes, of stomata, of epidermal cells, etc. For this study, samples of leaves were collected on more than one hundred species. (C) The analysis of inflorescence architecture and flower structure in relation to reproduction. After a quantitative analysis of the inflorescence and flower characters belonging to 75 species, it has been possible to make an allometric relationship between different characters in the overall family ( for example asymmetry of the inflorescence, length and angles of the paraclades, length of the perianth, the stamen, and the stigma, number of ovules, quantity of pollen, etc). The collection of Aroids (about 450 species and 50 genera) has been used for more thand 15 years to conduct projets on their floral morphology. By using inflorescences at different stages of development collected on specimens growing in the garden and in the wild, we have been able to to conduct three main projects. (A) The anatomy of the flower of different genera (e.g. Aglaonema, Monstera, Zamioculcas). (B) The presence of a morphogenetic gradient in the inflorescence of Cercestis, Culcasia and Philodendron, where we observe female flowers in the basal part of the inflorescence, male flowers in the upper part and bisexual flowers in the median part. (C) The interactions between physical and biological constraints in the structure of the inflorescence.

Key words: Araceae, begonia, development, flower, leaf, systematic