Saturday, October 10, 2015
Botany picture #215: Lemna disperma
No time to write something substantial, so here is another plant seen on our recent holiday trip. I have long found floating plants fascinating; and one of the most interesting aspects is how quickly and drastically their morphology changes compared to their closest relatives. In the case of duckweed like the above species, they are part of the Araceae family and thus represent perhaps the most extreme example of massive reduction in size and complexity found in all the flowering plants.
The species in this case is Lemna disperma. Or at least that is what the Flora of New South Wales suggests, I have not actually checked against a world wide key to the species of Lemna. The genus, however, is easily recognised. There are five genera of duckweeds, and simplifying a bit the really tiny rootless specks are Wolffia, rootless but larger and longish, often boomerang-shaped ones are Wolffiella, those with only one root per thallus are Lemna, and those with multiple roots are Landoldtia and Spirodela.
For those interested in more about the bizarre world of duckweeds, there is a tremendously detailed website available, although of course it has a bit of a focus on the country of its author.