From the CO2Science Archive: Unlike many plants in the archive, Lemna Gibba L. or Swollen Duckweed is not disparaged as invasive despite it spreading easily on many continents and despite what cannot be called a complimentary name and which would not be appropriate in a Western. It is a simple plant that grows on the surface of ponds forming a green mat and occasionally produces small flowers. We don’t even know why it is called swollen since it is so small, but in 1985 and 1990 experiments showed that an extra 300 ppm CO₂ boosted its growth by an average of 47% so Swollen Duckweed will continue to swell as long as we keep adding CO₂ to the air.