Seedling Diversity in Hydatellaceae: Implications for the Evolution of Angiosperm Cotyledons

Background and Aims Cotyledon number has long been a primary morphological feature distinguishing monocots from other angiosperms. Recent placement of Hydatellaceae near the early-divergent angiosperm order Nymphaeales, rather than in the monocot order Poales, has prompted reassessment of seedling morphology in this poorly known family.