Wolffia brasiliensis Weddell
Habitat: Mesotrophic to eutrophic waters of lakes, rivers, and backwaters. [Open water (non-forested, wetland)]
Range: Maine, Connecticut and Massachusetts south to Virginia, west to Kansas.
Aids to Identification: This tiny aquatic plant is one of the smallest flowering plants. It is found floating low in the water with a small portion in contact with the air. The thalli (undifferentiated plant tissues) are ovoid and slightly asymmetrical (mostly 0.5-1.5 mm x 0.3-1.0 mm) with no veins or roots. Wolffia brasiliensis is similar in appearance to W. columbiana. Post-mortem, W. brasiliensis is punctate (dotted) with brown pigment-cells.
Ecological characteristics: Wolffia species often grow in association with Lemna species (duckweed).
Phenology: Reproduces by vegetative budding. Flowers are rarely produced.
Synonyms: Former names include Wolffia papulifera C. Thompson; Bruniera punctata (Griseb.) Nieuwl.
Reason(s) for rarity: At northern limit of range.
Conservation considerations: None noted.