Field Survey
In July 2019, we conducted a regional survey of natural populations ofLemna minor . We located 34 sites consisting of lakes, wetlands,
ponds, and roadside ditches broadly distributed across southern Quebec,
Canada (Fig. 1). Within each site, we sampled from three microsites,
situated at least 10m apart and supporting a minimum of 10 L.
minor colonies. From each microsite, we collected 10 free-floating
colonies of Lemna minor . Colonies consisted of between 2-10
attached fronds. Since daughter fronds emerge from two meristematic
pockets located on the frond’s lower surface, frond genealogy is easily
inferred. For each colony we measured both frond area and root length of
the oldest frond by photographing the plant against a standard ruler and
later analysing the photos using ImageJ. This resulted in 30
measurements of each trait per site.