Duckweed: a family of extremes
Duckweeds, botanically known as the Lemnaceae or Lemnoideae, are a (sub)family of flowering plants known for its extreme features. It is an aquatic plant that typically floats in still or slow-moving fresh water, such as ponds, ditches and backwaters of lakes and streams. They are distributed all around the world, except in polar regions.
Duckweeds are the smallest flowering plants, with a size ranging from 1.5 cm (for Spirodela polyrhiza) to less than 1 mm (for Wolffia angusta). They show an extremely reduced anatomy, with a leaf-stem structure called a frond and, depending on the genus, roots (present in Spirodela, Landoltia and Lemna).
Despite their small size, they can cover vast areas of water due to their extremely fast growth. They are the fastest growing flowering plants, doubling their biomass under optimal conditions in about 2 to 5 days. They achieve this extreme growth rate by reproducing clonally, whereby a novel daughter frond grows from the mother frond and buds of to form an independent clone. Although they most commonly reproduce clonally, they can also reproduce sexually. Hereby, we arrive at another extreme reduction: duckweeds have the smallest flowers of any flowering plant. Wolffia globosa holds the record, with a flower diameter of 0.1–0.2 mm.
Because of its unique features, duckweeds have received much interest for the development of commercial applications (see Why Duckweed?) .
Interesting references
- Kenneth Acosta, Klaus J Appenroth, Ljudmilla Borisjuk, Marvin Edelman, Uwe Heinig, Marcel A K Jansen, Tokitaka Oyama, Buntora Pasaribu, Ingo Schubert, Shawn Sorrels, K Sowjanya Sree, Shuqing Xu, Todd P Michael, Eric Lam, Return of the Lemnaceae: duckweed as a model plant system in the genomics and postgenomics era, The Plant Cell, Volume 33, Issue 10, October 2021, Pages 3207–3234, https://doi.org/10.1093/plcell/koab189
