Canada mayflower and false solomons-seal are both placed in the genus Maianthemum on the basis of morphological evidence and results from analyses of DNA sequence variation. Canada mayflower resembles several other Maianthemum species in North America and Eurasia in having underground stems (rhizomes) that are quite narrow (mostly 2-3 mm in diameter); in contrast, the remaining species, including the two Ontario false solomons-seals, have much thicker rhizomes (5 mm or more in diameter). The cross-sectional anatomy of the rhizome of Canada mayflower is unexpectedly different from that of the false solomons-seals. Using collections made at the Koffler Scientific Reserve and elsewhere we are investigating whether this difference is found in other species with narrow rhizomes (it is). By integratingour anatomical results with the genealogy of all the species of Maianthemum we are able to make inferences about what may control how rhizome anatomy has evolved in this genus.
Marta Heckel, Ecology and Evolutionary Biology, University of Toronto