The lamina or blade in macroscopic algae, like seaweed, is a generally flattened structure that typically forms the principal bulk of the thallus.[1] It is often developed into specialised organs such as flotation bladders and reproductive organs.[citation needed]
The lamina is typically an expansion of the stipe which in term is attached to the substrate by the holdfast.[2]
^Hurd, Catriona L.; Harrison, Paul J.; Bischof, Kai; Lobban, Christopher S. (2014). Seaweed ecology and physiology (2nd ed.). Cambridge ; New York: Cambridge University Press. ISBN978-0-521-14595-4.