Evolution, systematics and diversity of Bryophytes. This research is laboratory and field-based with projects spanning Arctic Canada, the western Cordillera, and Madagascar. Current goals include:
1) Evolutionary relationship of basal bryophytes lineages with respect to land plants
2) Genetic evidence for bryophyte refugia in Beringia
3) Evolution of reproductive strategies in mosses
4) Systematic studies of the Dicranaceae.