Sunday, March 3, 2013
Botany picture #43: Azolla pinnata
Ricciocarpus natans. The photo above now shows a member of a third lineage to independently evolve this habit, the ferns. There are two small genera of free-floating ferns, Azolla and Salvinia, and this is Azolla pinnata (Salviniaceae).
Perhaps the most remarkable thing about Azolla is the "Azolla event": congeners of the plants pictured above are hypothesized to have played a crucial role in carbon sequestration 49 million years ago.